Method and apparatus for transmitting sidelink harq feedback in nr v2x

ABSTRACT

Provided herein are a method of transmitting a Sidelink Hybrid Automatic Repeat Request (SL HARQ) feedback by a first device and a device supporting the same. The method may include the steps of receiving a Physical Sidelink Shared Channel (PSSCH) from a second device, and transmitting a SL HARQ feedback related to the PSSCH to the second device, wherein a resource in which the SL HARQ feedback is transmitted is determined based on an identifier (ID) of the first device.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119 (e), this application claims the benefit ofU.S. Provisional Application No. 62/741,474 filed on Oct. 4, 2018, andInternational application No. PCT/KR2019/012906 filed on Oct. 2, 2019,the contents of which are all hereby incorporated by reference herein intheir entirety.

FIELD OF THE DISCLOSURE

This disclosure relates to a wireless communication system.

RELATED ART

A wireless communication system is a multiple access system thatsupports communication of multiple users by sharing available systemresources (e.g. a bandwidth, transmission power, etc.) among them.Examples of multiple access systems include a Code

Division Multiple Access (CDMA) system, a Frequency Division MultipleAccess (FDMA) system, a Time Division Multiple Access (TDMA) system, anOrthogonal Frequency Division Multiple Access (OFDMA) system, a SingleCarrier Frequency Division Multiple Access (SC-FDMA) system, and aMulti-Carrier Frequency Division Multiple Access (MC-FDMA) system.

Meanwhile, a wireless communication system may need to estimate anuplink channel or downlink channel to transmit/receive data, to achievesystem synchronization, and to feedback channel information. In awireless communication system environment, fading occurs by multipathtime delay. A process of recovering a transmitted signal by compensatingfor a signal distortion caused by drastic environmental changes byfading is referred to as channel estimation. Further, it is needed tomeasure a channel state with respect to a cell to which a user equipment(UE) belongs or another cell. For channel estimation or channel statemeasurement, channel estimation is generally performed using a referencesignal (RS) known between a transmitter and a receiver.

A UE may perform measurement using the following three methods.

1) Reference signal received power (RSRP): RSRP indicates the averagereceived power of all resource elements (REs) carrying CRSs transmittedover the entire band. Here, the UE may measure the average receivedpower of all REs carrying channel state information (CSI) RSs instead ofCRSs.

2) Received signal strength indicator (RSSI): RSSI indicates receivedpower measured over the entire band. RSSI includes all of a signal,interference, and thermal noise.

3) Reference symbol received quality (RSRQ): RSRQ indicates a channelquality indicator (CQI) and may be determined as RSRP/RSSI depending ona bandwidth or a sub-band. That is, RSRQ refers tosignal-to-interference-plus-noise-ratio (SINR). Since RSRP does notprovide sufficient mobility information, RSRQ may be used instead ofRSRP in a handover or cell reselection process.

RSRQ may be calculated by RSSI/RSSP. Alternatively, RSRQ may becalculated by N*RSSI/RSSP. Here, N may be a parameter (for example, thenumber of PRBs) or a function associated with a bandwidth in which RSSIis measured.

Meanwhile, sidelink (SL) communication is a communication scheme inwhich a direct link is established between User Equipments (UEs) and theUEs exchange voice and data directly with each other withoutintervention of an evolved Node B (eNB). SL communication is underconsideration as a solution to the overhead of an eNB caused by rapidlyincreasing data traffic.

Vehicle-to-everything (V2X) refers to a communication technology throughwhich a vehicle exchanges information with another vehicle, apedestrian, an object having an infrastructure (or infra) establishedtherein, and so on. The V2X may be divided into 4 types, such asvehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I),vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2Xcommunication may be provided via a PC5 interface and/or Uu interface.

Meanwhile, as a wider range of communication devices require largercommunication capacities, the need for mobile broadband communicationthat is more enhanced than the existing Radio Access Technology (RAT) isrising. Accordingly, discussions are made on services and user equipment(UE) that are sensitive to reliability and latency. And, a nextgeneration radio access technology that is based on the enhanced mobilebroadband communication, massive MTC, Ultra-Reliable and Low LatencyCommunication (URLLC), and so on, may be referred to as a new radioaccess technology (RAT) or new radio (NR). Herein, the NR may alsosupport vehicle-to-everything (V2X) communication.

SUMMARY OF THE DISCLOSURE

Meanwhile, for example, in case of SL communication being associatedwith a service having requirements of high reliability or a servicehaving requirements of relatively high reliability, SL HARQ feedbackoperations and/or mechanism of a user equipment (UE) may be useful. Forexample, in case multiple UEs perform HARQ feedback transmission,collision may occur between the HARQ feedback transmissions. This maylead to a service latency (or delay). Therefore, in case multiple UEsperform HARQ feedback transmission, a method for minimizing collisionand a device for supporting the same are needed.

According to an embodiment, provided herein is a method of transmittinga Sidelink Hybrid Automatic Repeat Request (SL HARQ) feedback by a firstdevice 100. The method may include the steps of receiving a PhysicalSidelink Shared Channel (PSSCH) from a second device 200, andtransmitting a SL HARQ feedback related to the PSSCH to the seconddevice 200, wherein a resource in which the SL HARQ feedback istransmitted may be determined based on an identifier (ID) of the firstdevice 100.

According to another embodiment, provided herein is a method forreceiving a Sidelink Hybrid Automatic Repeat Request (SL HARQ) feedbackby a second device 200. The method may include the steps of transmittinga Physical Sidelink Shared Channel (PSSCH) to a plurality of userequipments (UEs) within a group, and receiving an SL HARQ feedbackrelated to the PSSCH from the plurality of UEs, wherein a resource inwhich the SL HARQ feedback is received may be determined based onidentifiers (IDs) of the plurality of UEs.

According to another embodiment, provided herein is a first device 100transmitting a Sidelink Hybrid Automatic Repeat Request SL HARQ)feedback. The first device 100 may include one or more memories, one ormore transceivers, and one or more processors operatively connecting theone or more memories and the one or more transceivers, wherein theprocessor may be configured to control the transceiver 106 so as toreceive a Physical Sidelink Shared Channel (PSSCH) from a second device200, and to control the transceiver 106 so as to transmit a SL HARQfeedback related to the PSSCH to the second device 200, wherein aresource in which the SL HARQ feedback is transmitted may be determinedbased on an identifier (ID) of the first device 100.

A UE can efficiently perform SL communication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a structure of an LTE system, in accordance with anembodiment of the present disclosure.

FIG. 2 shows a radio protocol architecture of a user plane, inaccordance with an embodiment of the present disclosure.

FIG. 3 shows a radio protocol architecture of a control plane, inaccordance with an embodiment of the present disclosure.

FIG. 4 shows a structure of an NR system, in accordance with anembodiment of the present disclosure.

FIG. 5 shows a functional division between an NG-RAN and a 5GC, inaccordance with an embodiment of the present disclosure.

FIG. 6 shows a structure of a radio frame of an NR, in accordance withan embodiment of the present disclosure.

FIG. 7 shows a structure of a slot of an NR frame, in accordance with anembodiment of the present disclosure.

FIG. 8 shows an example of a BWP, in accordance with an embodiment ofthe present disclosure.

FIG. 9 shows a protocol stack for a SL communication, in accordance withan embodiment of the present disclosure.

FIG. 10 shows a protocol stack for a SL communication, in accordancewith an embodiment of the present disclosure.

FIG. 11 shows a UE performing V2X or SL communication, in accordancewith an embodiment of the present disclosure.

FIG. 12 shows a resource unit for V2X or SL communication, in accordancewith an embodiment of the present disclosure.

FIG. 13 shows procedures of a UE performing V2X or SL communicationaccording to a transmission mode (TM), in accordance with an embodimentof the present disclosure.

FIG. 14 shows a method of selecting a transmission resource by a UE, inaccordance with an embodiment of the present disclosure.

FIG. 15 shows three different cast types, in accordance with anembodiment of the present disclosure.

FIG. 16 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure.

FIG. 17 shows an HARQ feedback resource, in accordance with anembodiment of the present disclosure.

FIG. 18 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in a groupcast SL communication, in accordance with an embodimentof the present disclosure.

FIG. 19 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure.

FIG. 20 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure.

FIG. 21 shows a method for transmitting an SL HARQ feedback by a firstdevice 100, in accordance with an embodiment of the present disclosure.

FIG. 22 shows a method for receiving an SL HARQ feedback by a seconddevice 200, in accordance with an embodiment of the present disclosure.

FIG. 23 shows a communication system 1, in accordance with an embodimentof the present disclosure.

FIG. 24 shows wireless devices, in accordance with an embodiment of thepresent disclosure.

FIG. 25 shows a signal process circuit for a transmission signal, inaccordance with an embodiment of the present disclosure.

FIG. 26 shows another example of a wireless device, in accordance withan embodiment of the present disclosure.

FIG. 27 shows a hand-held device, in accordance with an embodiment ofthe present disclosure.

FIG. 28 shows a vehicle or an autonomous vehicle, in accordance with anembodiment of the present disclosure.

FIG. 29 shows a vehicle, in accordance with an embodiment of the presentdisclosure.

FIG. 30 shows an XR device, in accordance with an embodiment of thepresent disclosure.

FIG. 31 shows a robot, in accordance with an embodiment of the presentdisclosure.

FIG. 32 shows an AI device, in accordance with an embodiment of thepresent disclosure.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In various embodiments of the present disclosure, it shall beinterpreted that “I” and “,” indicate “and/or”. For example, “A/B” maymean “A and/or B”. Additionally, “A, B” may also mean “A and/or B”.Moreover, “AB/C” may mean “at least one of A, B and/or C”. Furthermore,“A, B, C” may also mean “at least one of A, B and/or C”.

Furthermore, in various embodiments of the present disclosure, it shallbe interpreted that “or” indicates “and/or”. For example, “A or B” mayinclude “only A”, “only B”, and/or “both A and B”. In other words, invarious embodiments of the present disclosure, it shall be interpretedthat “or” indicates “additionally or alternatively”.

The technology described below may be used in various wirelesscommunication systems such as code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and so on. TheCDMA may be implemented with a radio technology, such as universalterrestrial radio access (UTRA) or CDMA-2000. The TDMA may beimplemented with a radio technology, such as global system for mobilecommunications (GSM)/general packet ratio service (GPRS)/enhanced datarate for GSM evolution (EDGE). The OFDMA may be implemented with a radiotechnology, such as institute of electrical and electronics engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA(E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16eand provides backward compatibility with a system based on the IEEE802.16e. The UTRA is part of a universal mobile telecommunication system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTEuses the OFDMA in a downlink and uses the SC-FDMA in an uplink.LTE-advanced (LTE-A) is an evolution of the LTE.

5G NR is a successive technology of LTE-A corresponding to a newClean-slate type mobile communication system having the characteristicsof high performance, low latency, high availability, and so on. 5G NRmay use resources of all spectrum available for usage including lowfrequency bands of less than 1 GHz, middle frequency bands ranging from1 GHz to 10 GHz, high frequency (millimeter waves) of 24 GHz or more,and so on.

For clarity in the description, the following description will mostlyfocus on LTE-A or 5G NR. However, technical features of the presentdisclosure will not be limited only to this.

FIG. 1 shows a structure of an LTE system, in accordance with anembodiment of the present disclosure. This may also be referred to as anEvolved-UMTS Terrestrial Radio Access Network (E-UTRAN), or a Long TermEvolution (LTE)/LTE-A system.

Referring to FIG. 1, the E-UTRAN includes a base station (BS) 20, whichprovides a control plane and a user plane to a user equipment (UE) 10.The UE 10 may be fixed or mobile and may also be referred to by usingdifferent terms, such as Mobile Station (MS), User Terminal (UT),Subscriber Station (SS), Mobile Terminal (MT), wireless device, and soon. The base station 20 refers to a fixed station that communicates withthe UE 10 and may also be referred to by using different terms, such asevolved-NodeB (eNB), Base Transceiver System (BTS), Access Point (AP),and so on.

The base stations 20 are interconnected to one another through an X2interface. The base stations 20 are connected to an Evolved Packet Core(EPC) 30 through an S1 interface. More specifically, the base station 20are connected to a Mobility Management Entity (MME) through an S1-MMEinterface and connected to Serving Gateway (S-GW) through an S1-Uinterface.

The EPC 30 is configured of an MME, an S-GW, and a Packet DataNetwork-Gateway (P-GW). The MME has UE access information or UEcapability information, and such information may be primarily used in UEmobility management. The S-GW corresponds to a gateway having an E-UTRANas its endpoint. And, the P-GW corresponds to a gateway having a PacketData Network (PDN) as its endpoint.

Layers of a radio interface protocol between the UE and the network maybe classified into a first layer (L1), a second layer (L2), and a thirdlayer (L3) based on the lower three layers of an open systeminterconnection (OSI) model, which is well-known in the communicationsystem. Herein, a physical layer belonging to the first layer provides aphysical channel using an Information Transfer Service, and a RadioResource Control (RRC) layer, which is located in the third layer,executes a function of controlling radio resources between the UE andthe network. For this, the RRC layer exchanges RRC messages between theUE and the base station.

FIG. 2 shows a radio protocol architecture of a user plane, inaccordance with an embodiment of the present disclosure. FIG. 3 shows aradio protocol architecture of a control plane, in accordance with anembodiment of the present disclosure. The user plane is a protocol stackfor user data transmission, and the control plane is a protocol stackfor control signal transmission.

Referring to FIG. 2 and FIG. 3, a physical (PHY) layer belongs to theL1. A physical (PHY) layer provides an information transfer service to ahigher layer through a physical channel. The PHY layer is connected to amedium access control (MAC) layer. Data is transferred (or transported)between the MAC layer and the PHY layer through a transport channel. Thetransport channel is sorted (or categorized) depending upon how andaccording to which characteristics data is being transferred through theradio interface.

Between different PHY layers, i.e., a PHY layer of a transmitter and aPHY layer of a receiver, data is transferred through the physicalchannel. The physical channel may be modulated by using an orthogonalfrequency division multiplexing (OFDM) scheme and uses time andfrequency as radio resource.

The MAC layer provides services to a radio link control (RLC) layer,which is a higher layer of the MAC layer, via a logical channel. The MAClayer provides a function of mapping multiple logical channels tomultiple transport channels. The MAC layer also provides a function oflogical channel multiplexing by mapping multiple logical channels to asingle transport channel. The MAC layer provides data transfer servicesover logical channels.

The RLC layer performs concatenation, segmentation, and reassembly ofRadio Link Control Service Data Unit (RLC SDU). In order to ensurevarious quality of service (QoS) required by a radio bearer (RB), theRLC layer provides three types of operation modes, i.e., a transparentmode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM).An AM RLC provides error correction through an automatic repeat request(ARQ).

The radio resource control (RRC) layer is defined only in a controlplane. And, the RRC layer performs a function of controlling logicalchannel, transport channels, and physical channels in relation withconfiguration, re-configuration, and release of radio bearers. The RBrefers to a logical path being provided by the first layer (PHY layer)and the second layer (MAC layer, RLC layer, Packet Data ConvergenceProtocol (PDCP) layer) in order to transport data between the UE and thenetwork.

Functions of a PDCP layer in the user plane include transfer, headercompression, and ciphering of user data. Functions of a PDCP layer inthe control plane include transfer and ciphering/integrity protection ofcontrol plane data.

The configuration of the RB refers to a process for specifying a radioprotocol layer and channel properties in order to provide a particularservice and for determining respective detailed parameters and operationmethods. The RB may then be classified into two types, i.e., a signalingradio bearer (SRB) and a data radio bearer (DRB). The SRB is used as apath for transmitting an RRC message in the control plane, and the DRBis used as a path for transmitting user data in the user plane.

When an RRC connection is established between an RRC layer of the UE andan RRC layer of the E-UTRAN, the UE is in an RRC CONNECTED state, and,otherwise, the UE may be in an RRC IDLE state. In case of the NR, an RRCINACTIVE state is additionally defined, and a UE being in the RRCINACTIVE state may maintain its connection with a core network whereasits connection with the base station is released.

Downlink transport channels transmitting (or transporting) data from anetwork to a UE include a Broadcast Channel (BCH) transmitting systeminformation and a downlink Shared Channel (SCH) transmitting other usertraffic or control messages. Traffic or control messages of downlinkmulticast or broadcast services may be transmitted via the downlink SCHor may be transmitted via a separate downlink Multicast Channel (MCH).Meanwhile, uplink transport channels transmitting (or transporting) datafrom a UE to a network include a Random Access Channel (RACH)transmitting initial control messages and an uplink Shared Channel (SCH)transmitting other user traffic or control messages.

Logical channels existing at a higher level than the transmissionchannel and being mapped to the transmission channel may include aBroadcast Control Channel (BCCH), a Paging Control Channel (PCCH), aCommon Control Channel (CCCH), a Multicast Control Channel (MCCH), aMulticast Traffic Channel (MTCH), and so on.

A physical channel is configured of a plurality of OFDM symbols in thetime domain and a plurality of sub-carriers in the frequency domain. Onesubframe is configured of a plurality of OFDM symbols in the timedomain. A resource block is configured of a plurality of OFDM symbolsand a plurality of sub-carriers in resource allocation units.Additionally, each subframe may use specific sub-carriers of specificOFDM symbols (e.g., first OFDM symbol) of the corresponding subframe fora Physical Downlink Control Channel (PDCCH), i.e., L1/L2 controlchannels. A Transmission Time Interval (TTI) refers to a unit time of asubframe transmission.

FIG. 4 shows a structure of an NR system, in accordance with anembodiment of the present disclosure.

Referring to FIG. 4, a Next Generation-Radio Access Network (NG-RAN) mayinclude a next generation-Node B (gNB) and/or eNB providing a user planeand control plane protocol termination to a user. FIG. 4 shows a casewhere the NG-RAN includes only the gNB. The gNB and the eNB areconnected to one another via Xn interface. The gNB and the eNB areconnected to one another via 5^(th) Generation (5G) Core Network (5GC)and NG interface. More specifically, the gNB and the eNB are connectedto an access and mobility management function (AMF) via NG-C interface,and the gNB and the eNB are connected to a user plane function (UPF) viaNG-U interface.

FIG. 5 shows a functional division between an NG-RAN and a 5GC, inaccordance with an embodiment of the present disclosure.

Referring to FIG. 5, the gNB may provide functions, such as Inter CellRadio Resource Management (RRM), Radio Bearer (RB) control, ConnectionMobility Control, Radio Admission Control, Measurement Configuration &Provision, Dynamic Resource Allocation, and so on. An AMF may providefunctions, such as Non Access Stratum (NAS) security, idle statemobility processing, and so on. A UPF may provide functions, such asMobility Anchoring, Protocol Data Unit (PDU) processing, and so on. ASession Management Function (SMF) may provide functions, such as userequipment (UE) Internet Protocol (IP) address allocation, PDU sessioncontrol, and so on.

FIG. 6 shows a structure of a radio frame of an NR, in accordance withan embodiment of the present disclosure.

Referring to FIG. 6, in the NR, a radio frame may be used for performinguplink and downlink transmission. A radio frame has a length of 10 msand may be defined to be configured of two half-frames (HFs). Ahalf-frame may include five 1 ms subframes (SFs). A subframe (SF) may bedivided into one or more slots, and the number of slots within asubframe may be determined in accordance with subcarrier spacing (SCS).Each slot may include 12 or 14 OFDM(A) symbols according to a cyclicprefix (CP).

In case of using a normal CP, each slot may include 14 symbols. In caseof using an extended CP, each slot may include 12 symbols. Herein, asymbol may include an OFDM symbol (or CP-OFDM symbol) and a SingleCarrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM(DFT-s-OFDM) symbol).

Table 1 shown below represents an example of a number of symbols perslot (N^(slot) _(symb)), a number slots per frame (N^(fraem) _(slot)),and a number of slots per subframe (N^(subframe,u) _(slot)) inaccordance with an SCS configuration (u), in a case where a normal CP isused.

TABLE 1 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot)N^(subframe, u) _(slot) 15 KHz (u = 0) 14 10 1 30 KHz (u = 1) 14 20 2 60KHz (u = 2) 14 40 4 120 KHz (u = 3)  14 80 8 240 KHz (u = 4)  14 160 16

Table 2 shows an example of a number of symbols per slot, a number ofslots per frame, and a number of slots per subframe in accordance withthe SCS, in a case where an extended CP is used.

TABLE 2 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot)N^(subframe, u) _(slot) 60 KHz (u = 2) 12 40 4

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on)between multiple cells being integrate to one UE may be differentlyconfigured. Accordingly, a (absolute time) duration (or section) of atime resource (e.g., subframe, slot or TTI) (collectively referred to asa time unit (TU) for simplicity) being configured of the same number ofsymbols may be differently configured in the integrated cells.

In the NR, multiple numerologies or SCSs for supporting various 5Gservices may be supported. For example, in case an SCS is 15 kHz, a widearea of the conventional cellular bands may be supported, and, in casean SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrierbandwidth may be supported. In case the SCS is 60 kHz or higher, abandwidth that is greater than 24.25 GHz may be used in order toovercome phase noise.

An NR frequency band may be defined as two different types of frequencyranges. The two different types of frequency ranges may be FR1 and FR2.The values of the frequency ranges may be changed (or varied), and, forexample, the two different types of frequency ranges may be as shownbelow in Table 3. Among the frequency ranges that are used in an NRsystem, FR1 may mean a “sub 6 GHz range”, and FR2 may mean an “above 6GHz range” and may also be referred to as a millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing (SCS) FR1  450 MHz-6000 MHz 15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

As described above, the values of the frequency ranges in the NR systemmay be changed (or varied). For example, as shown below in Table 4, FR1may include a band within a range of 410 MHz to 7125 MHz. Morespecifically, FR1 may include a frequency band of 6 GHz (or 5850, 5900,5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz(or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1may include an unlicensed band. The unlicensed band may be used forvarious purposes, e.g., the unlicensed band for vehicle-specificcommunication (e.g., automated driving).

TABLE 4 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing (SCS) FR1  410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

FIG. 7 shows a structure of a slot of an NR frame, in accordance with anembodiment of the present disclosure.

Referring to FIG. 7, a slot includes a plurality of symbols in a timedomain. For example, in case of a normal CP, one slot may include 14symbols. However, in case of an extended CP, one slot may include 12symbols. Alternatively, in case of a normal CP, one slot may include 7symbols. However, in case of an extended CP, one slot may include 6symbols.

A carrier includes a plurality of subcarriers in a frequency domain. AResource Block (RB) may be defined as a plurality of consecutivesubcarriers (e.g., 12 subcarriers) in the frequency domain. A BandwidthPart (BWP) may be defined as a plurality of consecutive (Physical)Resource Blocks ((P)RBs) in the frequency domain, and the BWP maycorrespond to one numerology (e.g., SCS, CP length, and so on). Acarrier may include a maximum of N number BWPs (e.g., 5 BWPs). Datacommunication may be performed via an activated BWP. Each element may bereferred to as a Resource Element (RE) within a resource grid and onecomplex symbol may be mapped to each element.

Hereinafter, a Bandwidth Part (BWP) and a carrier will be described indetail.

The Bandwidth Part (BWP) may be a continuous set of physical resourceblocks (PRBs) within a given numerology. The PRB may be selected from acontinuous partial set of a common resource block (CRB) for a givennumerology on a given carrier.

When using Bandwidth Adaptation (BA), a receiving bandwidth and atransmitting bandwidth of a user equipment (UE) are not required to beas wide (or large) as the bandwidth of the cell, and the receivingbandwidth and the transmitting bandwidth of the UE may be controlled (oradjusted). For example, the UE may receive information/configuration forbandwidth control (or adjustment) from a network/base station. In thiscase, the bandwidth control (or adjustment) may be performed based onthe received information/configuration. For example, the bandwidthcontrol (or adjustment) may include reduction/expansion of thebandwidth, position change of the bandwidth, or change in subcarrierspacing of the bandwidth.

For example, the bandwidth may be reduced during a duration with littleactivity in order to save power. For example, a position of thebandwidth may be relocated (or moved) from a frequency domain. Forexample, the position of the bandwidth may be relocated (or moved) froma frequency domain in order to enhance scheduling flexibility. Forexample, subcarrier spacing of the bandwidth may be changed. Forexample, the subcarrier spacing of the bandwidth may be changed in orderto authorize different services. A subset of a total cell bandwidth of acell may be referred to as a Bandwidth Part (BWP). BA may be performedwhen a base station/network configures BWPs to the UE, and when the basestation/network notifies the BWP that is currently in an active state,among the BWPs, to the UE.

For example, the BWP may be one of an active BWP, an initial BWP, and/ora default BWP. For example, the UE may not monitor a downlink radio linkquality in a DL BWP other than the active DL BWP within a primary cell(PCell). For example, the UE may not receive a PDCCH, a PDSCH or aCSI-RS (excluding only the RRM) from outside of the active DL BWP. Forexample, the UE may not trigger a Channel State Information (CSI) reportfor an inactive DL BWP. For example, the UE may not transmit a PUCCH ora PUSCH from outside of an inactive DL BWP. For example, in case of adownlink, an initial BWP may be given as a continuous RB set for an RMSICORESET (that is configured by a PBCH). For example, in case of anuplink, an initial BWP may be given by a SIB for a random accessprocedure. For example, a default BWP may be configured by a higherlayer. For example, an initial value of a default BWP may be an initialDL BWP. For energy saving, if the UE fails to detect DCI during apredetermined period of time, the UE may switch the active BWP of the UEto a default BWP.

Meanwhile, a BWP may be defined for the SL. The same SL BWP may be usedfor transmission and reception. For example, a transmitting UE maytransmit an SL channel or SL signal within a specific BWP, and areceiving UE may receive an SL channel or SL signal within the samespecific BWP. In a licensed carrier, the SL BWP may be definedseparately from a Uu BWP, and the SL BWP may have a separateconfiguration signaling from the Uu BWP. For example, the UE may receivea configuration for an SL BWP from the base station/network. The SL BWPmay be configured (in advance) for an out-of-coverage NR V2X UE and anRRC IDLE UE. For a UE operating in the RRC CONNECTED mode, at least oneSL BWP may be activated within a carrier.

FIG. 8 shows an example of a BWP, in accordance with an embodiment ofthe present disclosure. In the embodiment of FIG. 8, it is assumed thatthree BWPs exist.

Referring to FIG. 8, a common resource block (CRB) may be a carrierresource block that is numerated from one end of a carrier band toanother end. And, a PRB may be a resource block that is numerated withineach BWP. Point A may indicate a common reference point for a resourceblock grid.

A BWP may be configured by Point A, an offset (N^(start) _(BWP)) fromPoint A, and a bandwidth (N^(size) _(BWP)). For example, Point A may bean external reference point of a PRB of a carrier having subcarrier 0 ofall numerologies (e.g., all numerologies being supported by the networkwithin the corresponding carrier) aligned therein. For example, theoffset may be a PRB distance between a lowest subcarrier within a givennumerology and Point A. For example, the bandwidth may be a number ofPRBs within the given numerology.

Hereinafter, V2X or SL communication will be described.

FIG. 9 shows a protocol stack for a SL communication, in accordance withan embodiment of the present disclosure. More specifically, (a) of FIG.9 shows a user plane protocol stack of LTE, and (b) of FIG. 9 shows acontrol plane protocol stack of LTE.

FIG. 10 shows a protocol stack for a SL communication, in accordancewith an embodiment of the present disclosure. More specifically, (a) ofFIG. 10 shows a user plane protocol stack of NR, and (b) of FIG. 10shows a control plane protocol stack of NR.

Hereinafter, SL Synchronization Signal (SLSS) and synchronizationinformation will be described.

SLSS is a SL specific sequence, which may include a Primary SidelinkSynchronization Signal (PSSS) and a Secondary Sidelink SynchronizationSignal (SSSS). The PSSS may also be referred to as a Sidelink PrimarySynchronization Signal (S-PSS), and the SSSS may also be referred to asa Sidelink Secondary Synchronization Signal (S-SSS).

A Physical Sidelink Broadcast Channel (PSBCH) may be a (broadcast)channel through which basic (system) information that should first beknown by the user equipment (UE) before transmitting and receiving SLsignals. For example, the basic information may be information relatedto SLSS, a Duplex mode (DM), Time Division Duplex Uplink/Downlink (TDDUL/DL) configuration, information related to a resource pool,application types related to SLSS, a subframe offset, broadcastinformation, and so on.

The S-PSS, the S-SSS, and the PSBCH may be included in a block format(e.g., a SL SS/PSBCH block, hereinafter referred to asSidelink-Synchronization Signal Block (S-SSB)). The S-SSB may have thesame numerology (i.e., SCS and CP length) as a Physical Sidelink ControlChannel (PSCCH)/Physical Sidelink Shared Channel (PSSCH) within thecarrier, and a transmission bandwidth may exist within a(pre-)configured SL Bandwidth Part (BWP). And, a frequency position ofthe S-SSB may be (pre-)configured. Therefore, the UE is not required toperform a hypothesis detection in order to discover the S-SSB in thecarrier.

Each SLSS may have a physical layer SL synchronization identity (ID),and the respective value may be equal to any one value ranging from 0 to335. Depending upon one of the above-described values that is used, asynchronization source may also be identified. For example, values of 0,168, 169 may indicate global navigation satellite systems (GNSS), valuesfrom 1 to 167 may indicate base stations, and values from 170 to 335 mayindicate that the source is outside of the coverage. Alternatively,among the physical layer SL synchronization ID values, values 0 to 167may correspond to value being used by a network, and values from 168 to335 may correspond to value being used outside of the network coverage.

FIG. 11 shows a UE performing V2X or SL communication, in accordancewith an embodiment of the present disclosure.

Referring to FIG. 11, in V2X/SL communication, the term terminal maymainly refer to a terminal (or equipment) used by a user. However, incase a network equipment, such as a base station, transmits and receivessignals in accordance with a communication scheme between the networkequipment and a user equipment (UE) (or terminal), the base station mayalso be viewed as a type of user equipment (or terminal).

User equipment 1 (UE1) may select a resource unit corresponding to aspecific resource within a resource pool, which refers to a set ofresources, and UE1 may then be operated so as to transmit a SL signal byusing the corresponding resource unit. User equipment 2 (UE2), which isto a receiving UE, may be configured with a resource pool to which UE1can transmit signals, and may then detect signals of UE1 from thecorresponding resource pool.

Herein, in case UE1 is within a connection range of the base station,the base station may notify the resource pool. Conversely, in case UE1is outside a connection range of the base station, another UE may notifythe resource pool or a pre-determined resource may be used.

Generally, a resource pool may be configured in a plurality of resourceunits, and each UE may select one resource unit or a plurality ofresource units and may use the selected resource unit(s) for its SLsignal transmission.

FIG. 12 shows a resource unit for V2X or SL communication, in accordancewith an embodiment of the present disclosure.

Referring to FIG. 12, the total frequency resources of the resource poolmay be divided into N_(F) number of resource units, the total timeresources of the resource pool may be divided into N_(T) number ofresource units. Therefore, a total of N_(F)*N_(T) number of resourceunits may be defined in the resource pool. FIG. 12 shows an example of acase where the corresponding resource pool is repeated at a cycle ofN_(T) number of subframes.

As shown in FIG. 12, one resource unit (e.g., Unit #0) may beperiodically and repeatedly indicated. Alternatively, in order toachieve a diversity effect in the time or frequency level (ordimension), an index of a physical resource unit to which a logicalresource unit is mapped may be changed to a pre-determined pattern inaccordance with time. In such resource unit structure, the resource poolmay refer to a set of resource units that can be used for a transmissionthat is performed by a user equipment (UE), which intends to transmit SLsignals.

The resource pool may be segmented to multiple types. For example,depending upon the content of a SL signal being transmitted from eachresource pool, the resource pool may be divided as described below.

(1) Scheduling Assignment (SA) may correspond to a signal includinginformation, such as a position of a resource that is used for thetransmission of a SL data channel, a Modulation and Coding Scheme (MCS)or Multiple Input Multiple Output (MIMO) transmission scheme needed forthe modulation of other data channels, a Timing Advance (TA), and so on.The SA may also be multiplexed with SL data within the same resourceunit and may then be transmitted, and, in this case, an SA resource poolmay refer to a resource pool in which the SA is multiplexed with the SLdata and then transmitted. The SA may also be referred to as a SLcontrol channel.

(2) A Physical Sidelink Shared Channel (PSSCH) may be a resource poolthat is used by a transmitting UE for transmitting user data. If the SAis multiplexed with SL data within the same resource unit and thentransmitted, only a SL data channel excluding the SA information may betransmitted from the resource pool that is configured for the SL datachannel. In other words, REs that were used for transmitting SAinformation within a separate resource unit of the SA resource pool maystill be used for transmitting SL data from the resource pool of a SLdata channel.

(3) A discovery channel may be a resource pool that is used by thetransmitting UE for transmitting information, such as its own ID. Bydoing so, the transmitting UE may allow a neighboring UE to discover thetransmitting UE.

Even if the content of the above-described SL signal is the same,different resource pools may be used depending upon thetransmission/reception attribute of the SL signal. For example, even ifthe same SL data channel or discovery message is used, the resource poolmay be identified as a different resource pool depending upon atransmission timing decision method (e.g., whether the transmission isperformed at a reception point of the synchronization reference signalor whether transmission is performed at the reception point by applyinga consistent timing advance), a resource allocation method (e.g.,whether the base station designates a transmission resource of aseparate signal to a separate transmitting UE or whether a separatetransmitting UE selects a separate signal transmission resource on itsown from the resource pool), and a signal format (e.g., a number ofsymbols occupied by each SL signal within a subframe or a number ofsubframes being used for the transmission of one SL signal) of the SLsignal, signal intensity from the base station, a transmitting powerintensity (or level) of a SL UE, and so on.

Hereinafter, resource allocation in a SL will be described.

FIG. 13 shows procedures of a UE performing V2X or SL communicationaccording to a transmission mode (TM), in accordance with an embodimentof the present disclosure. Specifically, (a) of FIG. 13 shows a UEoperation related to a transmission mode 1 or a transmission mode 3, and(b) of FIG. 13 shows a UE operation related to a transmission mode 2 ora transmission mode 4.

Referring to (a) of FIG. 13, in transmission modes 1/3, the base stationperforms resource scheduling to UE1 via PDCCH (more specifically,Downlink Control Information (DCI)), and UE1 performs SL/V2Xcommunication with UE2 according to the corresponding resourcescheduling. After transmitting sidelink control information (SCI) to UE2via physical sidelink control channel (PSCCH), UE1 may transmit databased on the SCI via physical sidelink shared channel (PSSCH). In caseof an LTE SL, transmission mode 1 may be applied to a general SLcommunication, and transmission mode 3 may be applied to a V2X SLcommunication.

Referring to (b) of FIG. 13, in transmission modes 2/4, the UE mayschedule resources on its own. More specifically, in case of LTE SL,transmission mode 2 may be applied to a general SL communication, andthe UE may select a resource from a predetermined resource pool on itsown and may then perform SL operations. Transmission mode 4 may beapplied to a V2X SL communication, and the UE may carry out a sensing/SAdecoding procedure, and so on, and select a resource within a selectionwindow on its own and may then perform V2X SL operations. Aftertransmitting the SCI to UE2 via PSCCH, UE1 may transmit SCI-based datavia PSSCH. Hereinafter, the transmission mode may be abbreviated to theterm mode.

In case of NR SL, at least two types of SL resource allocation modes maybe defined. In case of mode 1, the base station may schedule SLresources that are to be used for SL transmission. In case of mode 2,the user equipment (UE) may determine a SL transmission resource from SLresources that are configured by the base station/network orpredetermined SL resources. The configured SL resources or thepre-determined SL resources may be a resource pool. For example, in caseof mode 2, the UE may autonomously select a SL resource fortransmission. For example, in case of mode 2, the UE may assist (orhelp) SL resource selection of another UE. For example, in case of mode2, the UE may be configured with an NR configured grant for SLtransmission. For example, in case of mode 2, the UE may schedule SLtransmission of another UE. And, mode 2 may at least support reservationof SL resources for blind retransmission.

Procedures related to sensing and resource (re-)selection may besupported in resource allocation mode 2. The sensing procedure may bedefined as a process decoding the SCI from another UE and/or SLmeasurement. The decoding of the SCI in the sensing procedure may atleast provide information on a SL resource that is being indicated by aUE transmitting the SCI. When the corresponding SCI is decoded, thesensing procedure may use L1 SL Reference Signal Received Power (RSRP)measurement, which is based on SL Demodulation Reference Signal (DMRS).The resource (re-)selection procedure may use a result of the sensingprocedure in order to determine the resource for the SL transmission.

FIG. 14 shows a method of selecting a transmission resource by a UE, inaccordance with an embodiment of the present disclosure.

Referring to FIG. 14, the UE may identify transmission resourcesreserved by another UE or resources being used by another UE via sensingwithin a sensing window, and, after excluding the identified resourcesfrom a selection window, the UE may randomly select a resource fromresources having low interference among the remaining resources.

For example, within the sensing window, the UE may decode the PSCCHincluding information on the cycles of the reserved resources, and,then, the UE may measure a PSSCH RSRP from resources that areperiodically determined based on the PSCCH. The UE may exclude resourceshaving the PSSCH RSRP that exceeds a threshold value from the selectionwindow. Thereafter, the UE may randomly select a SL resource from theremaining resources within the selection window.

Alternatively, the UE may measure a Received Signal Strength Indicator(RSSI) of the periodic resources within the sensing window and may thendetermine the resources having low interference (e.g., the lower 20% ofthe resources). Additionally, the UE may also randomly select a SLresource from the resources included in the selection window among theperiodic resources. For example, in case the UE fails to performdecoding of the PSCCH, the UE may use the above described methods.

FIG. 15 shows three different cast types, in accordance with anembodiment of the present disclosure.

More specifically, (a) of FIG. 15 shows a broadcast type SLcommunication, (b) of FIG. 15 shows a unicast type SL communication, and(c) of FIG. 15 shows a groupcast type SL communication. In case of thebroadcast type SL communication, the UE may perform one-to-onecommunication with another UE. And, in case of the unicast type SLcommunication, the UE may perform SL communication with one or moreother UEs within the group to which the corresponding UE belongs. In thevarious embodiments of the present disclosure, the SL groupcastcommunication may be replaced with SL multicast communication, SLone-to-many communication, and so on.

Hereinafter, a Hybrid Automatic Repeat Request (HARQ) procedure in an SLwill be described in detail.

In case of SL unicast and SL groupcast, HARQ feedback and HARQ combiningin a physical layer may be supported. For example, in case a receivingUE operates in a Resource Allocation Mode 1 or 2, the receiving UE mayreceive a PSSCH from a transmitting UE, and the receiving UE maytransmit an HARQ feedback corresponding to the PSSCH to the transmittingUE by using a Sidelink Feedback Control Information (SFCI) format viaPhysical Sidelink Feedback Channel (PSFCH).

For example, an SL HARQ feedback may be enabled for the unicast. In thiscase, in a non-Code Block Group (non-CBG), the receiving UE may decode aPSCCH targeting the receiving UE, and, when the receiving UEsuccessfully decodes a transport block associated with the PSCCH, thereceiving UE may generate an HARQ-ACK. Thereafter, the receiving UE maytransmit the HARQ-ACK to the transmitting UE. Conversely, after thereceiving UE decodes the PSCCH targeting the receiving UE, if thereceiving UE fails to successfully decode a transport block associatedwith the PSCCH, the receiving UE may generate an HARQ-NACK, and thereceiving UE may transmit the HARQ-NACK to the transmitting UE.

For example, an SL HARQ feedback may be enabled for the groupcast. Forexample, during the non-CBG, two different types of HARQ feedbackoptions may be supported for the groupcast.

(1) Groupcast option 1: After decoding a PSCCH targeting the receivingUE, if the receiving UE fails to decode a transport block associatedwith the PSCCH, the receiving UE may transmit an HARQ-NACK to atransmitting UE via a PSFCH. Conversely, when a receiving UE decodes aPSCCH targeting the receiving UE, and when the receiving UE successfullydecodes a transport block associated with the PSCCH, the receiving UEmay not transmit an HARQ-ACK to a transmitting UE.

(2) Groupcast option 2: After decoding a PSCCH targeting the receivingUE, if the receiving UE fails to decode a transport block associatedwith the PSCCH, the receiving UE may transmit an HARQ-NACK to atransmitting UE via a PSFCH. And, when the receiving UE decodes a PSCCHtargeting the receiving UE, and when the receiving UE successfullydecodes a transport block associated with the PSCCH, the receiving UEmay transmit an HARQ-ACK to a transmitting UE via the PSFCH.

Meanwhile, for example, in case of SL communication being associatedwith a service having requirements of high reliability or a servicehaving requirements of relatively high reliability, SL HARQ feedbackoperations and/or mechanism of a user equipment (UE) may be useful. Forexample, in case of SL communication being associated with a servicehaving requirements of high reliability, an operation (or action) oftransmitting an SL HARQ feedback to a UE having transmitted the serviceby a UE having received the corresponding service may be useful insatisfying the requirements of high reliability.

Hereinafter, in accordance with various embodiments of the presentdisclosure, a method of determining a resource or transmission powerassociated with an SL HARQ feedback transmission by a UE and a devicefor supporting the same will be described in detail. In the variousembodiments of the present disclosure, the SL communication may includeV2X communication.

At least one of the methods that are proposed in accordance with thevarious embodiments of the present disclosure may be applied to at leastone of unicast communication, groupcast communication, and/or broadcastcommunication.

At least one of the methods that are proposed in accordance with thevarious embodiments of the present disclosure may be applied not only toPC5 interface or SL interface (e.g., PSCCH, PSSCH, PSBCH, PSSS/SSSS, andso on) based SL communication or V2X communication but also to Uuinterface (e.g., PUSCH, PDSCH, PDCCH, PUCCH, and so on) based SLcommunication or V2X communication.

In the various embodiments of the present disclosure, the receivingoperation (or action) of the UE may include a decoding operation and/orreceiving operation of an SL channel and/or SL signal (e.g., PSCCH,PSSCH, PSFCH, PSBCH, PSSS/SSSS, and so on). The receiving operation ofthe UE may include a decoding operation and/or receiving operation of aWAN DL channel and/or WAN DL signal (e.g., PDCCH, PDSCH, PSS/SSS, and soon). The receiving operation of the UE may include a sensing operationand/or CBR measuring operation. In the various embodiments of thepresent disclosure, the sensing operation of the UE may include a PSSCHDM-RS sequence based PSSCH-RSRP measuring operation, a PSSCH-RSRPmeasuring operation based on a PSSCH DM-RS sequence, which is scheduledby a PSCCH that is successfully decoded by the UE, a sidelink RSSI(S-RSSI) measuring operation, and/or an S-RSSI measuring operation basedon a subchannel being associated with a V2X resource pool. In thevarious embodiments of the present disclosure, the transmittingoperation of the UE may include a transmitting operation of an SLchannel and/or SL signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS/SSSS,and so on). The transmitting operation may include a transmittingoperation of a WAN UL channel and/or WAN UL signal (e.g., PUSCH, PUCCH,SRS, and so on). In the various embodiments of the present disclosure, asynchronization signal may include an SLSS and/or a PSBCH.

In the various embodiments of the present disclosure, configuration mayinclude signaling, signaling from a network, configuration from anetwork, and/or a pre-configuration from a network. In the variousembodiments of the present disclosure, definition may include signaling,signaling from a network, configuration from a network, and/or apre-configuration from a network. In the various embodiments of thepresent disclosure, designation may include signaling, signaling from anetwork, configuration from a network, and/or a pre-configuration from anetwork.

In the various embodiments of the present disclosure, ProSe Per PacketPriority (PPPP) may be replaced with ProSe Per Packet Reliability(PPPR), and PPPR may be replaced with PPPP. For example, as the PPPPvalue becomes smaller, this may indicate a high priority level, and, asthe PPPP value becomes greater, this may indicate a low priority level.For example, as the PPPP value becomes smaller, this may indicate a highreliability level, and, as the PPPP value becomes greater, this mayindicate a low reliability level. For example, a PPPP value related to aservice, packet or message being associated with a high priority levelmay be smaller than a PPPP value related to a service, packet or messagebeing associated with a low priority level. For example, a PPPP valuerelated to a service, packet or message being associated with a highreliability level may be smaller than a PPPP value related to a service,packet or message being associated with a low reliability level.

In the various embodiments of the present disclosure, a session mayinclude at least one of a unicast session (e.g., a unicast session forSL), a groupcast/multicast session (e.g., a groupcast/multicast sessionfor SL), and/or a broadcast session (e.g., a broadcast session for SL).

In the various embodiments of the present disclosure, a carrier may beinterchangeably extendedly interpreted as at least one of a BWP and/orresource pool. For example, a carrier may include at least one of a BWPand/or resource pool. For example, a carrier may include at least one ormore BWPs. For example, a BWP may include one or more resource pool.

In the various embodiments of the present disclosure, an HARQ feedbackresource may include an HARQ feedback transmission resource and/or anHARQ feedback reception resource. For example, the HARQ feedbacktransmission resource may include a resource for transmitting an HARQfeedback and/or a resource associated with the transmission of an HARQfeedback. For example, the HARQ feedback reception resource may includea resource for receiving an HARQ feedback and/or a resource associatedwith the reception of an HARQ feedback.

In the various embodiments of the present disclosure, a PSSCH resourcemay include a PSSCH transmission resource and/or PSSCH receptionresource. For example, the PSSCH transmission resource may include aresource for transmitting the PSSCH and/or a resource associated withthe transmission of the PSSCH. For example, the PSSCH reception resourcemay include a resource for receiving the PSSCH and/or a resourceassociated with the reception of the PSSCH.

In the various embodiments of the present disclosure, a PSCCH resourcemay include a PSCCH transmission resource and/or PSCCH receptionresource. For example, the PSCCH transmission resource may include aresource for transmitting the PSCCH and/or a resource associated withthe transmission of the PSCCH. For example, the PSCCH reception resourcemay include a resource for receiving the PSCCH and/or a resourceassociated with the reception of the PSCCH.

In the various embodiments of the present disclosure, the resource mayinclude at least one of a time domain resource, a frequency domainresource, and/or a code domain resource.

For example, in case resource collision occurs during at least one of aPSSCH transmission, a PSCCH transmission and/or an HARQ feedbacktransmission, it may be difficult for the SL HARQ feedback procedureand/or operation of the UE to be correctly executed. For example, incase resource collision occurs during at least one of a PSSCHtransmission, a PSCCH transmission and/or an HARQ feedback transmission,it may be difficult for the overall SL HARQ feedback procedure and/oroperation of the UE to be accurately executed.

For example, although the receiving UE has successfully received thePSSCH, in case an error occurs in the HARQ feedback (e.g., HARQ ACK) dueto the resource collision, the transmission UE may have to unnecessarilyretransmit the PSSCH to the receiving UE. For example, in case thereceiving UE fails to receive the PSSCH and the HARQ feedback fails tobe transmitted to the transmitting UE due to the resource collision, theSL communication related reliability or capability (or performance) maybe degraded. For example, in case the receiving UE fails to receive thePSCCH and/or PSSCH being transmitted from the transmitting UE, and incase an HARQ NACK corresponding to the PSCCH and/or PSSCH fails to becorrectly delivered to the transmitting UE due to the resourcecollision, the SL communication related reliability or performance (orcapability) may be degraded. Therefore, the HARQ feedback resource mayneed to be determined so that the collision between the plurality of UEscan be prevented or minimized.

FIG. 16 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure. Theembodiment of FIG. 16 may be combined with other various embodiments.

Referring to FIG. 16, in step S1610, a transmitting UE may transmit aPSCCH and/or PSSCH to a receiving UE. For example, the transmitting UEmay transmit SL information to the receiving UE by using a PSCCHresource and/or a PSSCH resource. For example, the SL information mayinclude at least one of SL control information, SL data, SL packet, SLTransport Block (TB), SL message and/or SL service.

In step S1620, the receiving UE may determine an HARQ feedback resource.Additionally, for example, the transmitting UE may determine the HARQfeedback resource.

For example, the HARQ feedback resource may be configured to have acorrelation or linkage with the PSSCH. For example, the HARQ feedbackresource may include at least one of a time domain resource, a frequencydomain resource, and/or a code domain resource. For example, a positionof the HARQ feedback resource may be configured to have correlation orlinkage with a position of a linked PSSCH resource based on apre-defined function. For example, the HARQ feedback resource may bedetermined based on at least one of information on a time domain relatedto the PSSCH, information on a frequency domain related to the PSSCH,and/or information on a code domain related to the PSSCH.

Additionally/Alternatively, for example, the HARQ feedback resource maybe configured to have a correlation or linkage with the PSCCH. Forexample, a position of the HARQ feedback resource may be configured tohave correlation or linkage with a position of a linked PSCCH resourcebased on a pre-defined function. For example, the HARQ feedback resourcemay be determined based on at least one of information on a time domainrelated to the PSCCH, information on a frequency domain related to thePSCCH, and/or information on a code domain related to the PSCCH.

For example, the HARQ feedback resource may be configured in a subsetformat of a frequency resource that is used for PSSCH transmissionand/or PSCCH transmission. For example, the frequency domain of the HARQfeedback resource may be configured in a subset format of a frequencydomain of a linked PSSCH resource and/or PSCCH resource. For example,the frequency domain of the HARQ feedback resource may be included inthe frequency domain of a PSSCH resource and/or PSCCH resource.

FIG. 17 shows an HARQ feedback resource, in accordance with anembodiment of the present disclosure. The embodiment of FIG. 17 may becombined with other various embodiments.

Referring to FIG. 17, a transmitting UE may transmit a PSCCH and/orPSSCH to a receiving UE via 4 subchannels. In this case, the frequencydomain of an HARQ feedback resource associated with the PSCCH and/orPSSCH may correspond to a subset of the frequency resource being used bythe transmitting UE for transmitting a PSCCH and/or PSSCH.

According to an embodiment of the present disclosure, a time gap betweenan HARQ feedback resource and a PSSCH resource may be configured.Additionally/Alternatively, for example, a time gap between an HARQfeedback resource and a PSCCH resource may be configured. For example,based on the decoding capability and/or latency requirements (e.g., V2Xmessage and/or service related latency requirements) of the UE, a timegap may be configured between a PSCCH and/or PSSCH reception point of areceiving UE and an HARQ feedback transmission point of the receivingUE. For example, based on the decoding capability and/or latencyrequirements of the UE, a time gap may be configured between an HARQfeedback reception point of a transmitting UE and a PSSCH and/or PSCCH(re-)transmission point of the transmitting UE.

For example, the time gap may be commonly configured in a resource pool.For example, the time gap may be commonly configured between differentUEs within a resource pool. For example, the time gap may be commonlyconfigured to the transmitting UE and the receiving UE. Therefore, theUE may simply determine the HARQ feedback. For example, the time gap maybe resource pool-specifically configured.

For example, among a latency budget of services co-existing in aresource pool, the time gap may be configured or designated to have avalue less than and/or equal to the smallest latency budget value. Forexample, in case service A and service B co-exist in the resource pool,and in case the latency budget of service A is smaller than the latencybudget of service B, the time gap may be configured or designated tohave a value that is less than or equal to the latency budget of serviceA.

For example, the time gap may be designated so that a maximum number ofretransmissions related to a transport block (TB), which is specificallyconfigured according to a resource pool, a service type, a servicepriority level, a cast type, and/or QoS requirements of the service, can(all) be supported/performed in a latency budget for a (related) servicewithin the resource pool. For example, the maximum number ofretransmissions may be a maximum allowable number of retransmissionsincluding an initial transmission.

For example, among the decoding capabilities of the UE, the time gap maybe configured or designated to have a value greater than and/or equal tothe greatest (or largest) decoding capability value. Herein, forexample, the decoding capability may be a processing time of the UE thatis needed starting from a PSSCH reception end time of the UE to a PSFCHtransmission start time of the UE. Additionally/Alternatively, forexample, the decoding capability may be a processing time of the UE thatis needed starting from a PSCCH reception end time of the UE to a PSFCHtransmission start time of the UE. For example, among the decodingcapabilities of the UE within a resource pool, the time gap may beconfigured or designated to have a value greater than and/or equal tothe greatest (or largest) decoding capability value. For example, incase UE A, UE B, and UE C perform SL communication within the resourcepool, and in case the decoding capability of UE A is the leastfavorable, the time gap may be configured or designated to have a valuegreater than and/or equal to the processing time that is requiredstarting from starting from a PSSCH and/or PSCCH reception end time ofUE A to a PSFCH transmission start time of UE A.

For example, the time gap may be differently or independently configuredper service type, service priority level, SL communication type, asession related to the service, PPPP related to the service, PPPRrelated to service, a Block Error Rate (BLER) related to the service, aSignal to Interference plus Noise Ratio (SINR) related to the service, alatency budget related to the service, and/or UE capability. Forexample, the time gap may be differently or independently configured perservice type, service priority level, SL communication type, a sessionrelated to the service, PPPP related to the service, PPPR related toservice, a BLER related to the service, a SINR related to the service, alatency budget related to the service, and/or UE capability within theresource pool. For example, the SL communication type may include atleast one of unicast, groupcast, and/or broadcast.

Referring back to FIG. 16, in step S1630, the receiving UE may transmitan HARQ feedback to the transmitting UE. For example, the receiving UEmay transmit an HARQ feedback corresponding to the PSCCH and/or PSSCH tothe transmitting UE. For example, the receiving UE may transmit the HARQfeedback to the transmitting UE by using an HARQ feedback resource,which is determined based on the PSCCH resource and/or PSSCH resource.For example, the transmitting UE may receive an HARQ feedback from thereceiving UE within an HARQ feedback resource, which is determined basedon the PSCCH resource and/or PSSCH resource.

For example, in case the receiving UE successfully receives the PSCCHand/or PSSCH, the HARQ feedback may be an HARQ ACK. For example, in casethe receiving UE fails to receive the PSCCH and/or PSSCH, the HARQfeedback may correspond to at least one of an HARQ NACK and/or adiscontinuous detection (DTX).

According to an embodiment of the present disclosure, in case of agroupcast, wherein a plurality of UEs within a group perform SLcommunication with one another, the HARQ feedback resource may beimplemented as two different types.

(1) Option A: A common HARQ feedback resource may be configured betweenreceiving UEs. For example, in case a transmitting UE transmits a PSSCHand/or PSCCH to a plurality of receiving UEs, the HARQ feedback resourcemay be commonly configured for the plurality of receiving UEs that havereceived the PSSCH and/or PSCCH.

(2) Option B: HARQ feedback resources each being different orindependent from one another may be configured between receiving UEs.For example, HARQ feedback resources each being different or independentfrom one another may be configured per receiving UE or per sub-groupincluding one or more receiving UEs. For example, in case a transmittingUE transmits a PSSCH and/or PSCCH to a plurality of receiving UEs, HARQfeedback resources each being different or independent from one anothermay each be configured for a plurality of receiving UEs that havereceived the PSSCH and/or PSCCH or for a plurality of sub-groups.

For example, Option A may be limitedly applied only to the Groupcastoption 1. For example, in Groupcast option 1, a plurality of receivingUEs may transmit an HARQ NACK to the transmitting UE by using an HARQfeedback resource, which is commonly configured for the plurality ofreceiving UEs, only in case the plurality of receiving UEs have failedto receive the PSSCH and/or PSCCH. For example, the HARQ NACK may beimplemented in a Single Frequency Network (SFN) format. In this case,the transmitting UE may not be capable of separating and receiving theHARQ NACKs transmitted from the plurality of receiving UEs. Therefore,the transmitting UE may not be capable of knowing which receiving UE hastransmitted the HARQ NACK. However, the transmitting UE may know that atleast one receiving UE, among the plurality of receiving UEs, hastransmitted the HARQ NACK, and the transmitting UE may retransmit thePSSCH and/or PSCCH to the plurality of receiving UEs.

For example, in case of Option A, a unicast related HARQ feedbackresource structure may be re-used. Additionally/Alternatively, forexample, in case of Option A, an overhead related to the HARQ feedbackresource may be decreased. Conversely, in case of Option A, there may belimitations in that the transmitting UE cannot determine/recognize aDTX. For example, in case the transmitting UE has transmitted the PSSCHand/or PSCCH to the receiving UE, the receiving UE may fail to receive aPSCCH, which schedules the PSSCH. In this case, according to Option A,the receiving UE may not transmit the HARQ NACK to the transmitting UE.Therefore, there may occur a problem where the transmitting UEmisinterprets that the receiving UE has successfully received the PSSCH.

For example, in case of Option B, within a group including a pluralityof receiving UEs, HARQ feedback resources each being different orindependent from one another may be allocated per receiving UE orsub-group. Herein, for example, according to Option B, as the number ofreceiving UEs or the number of sub-groups included in the group becomeslarger, a larger amount of HARQ feedback resources may be required. Forexample, in case of a group including N number of receiving UEs, N−1number of HARQ feedback resources may be required. For example, Option Bmay be limitedly applied only to the Groupcast option 2.

FIG. 18 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in a groupcast SL communication, in accordance with an embodimentof the present disclosure. The embodiment of FIG. 18 may be combinedwith other various embodiments.

In the embodiment of FIG. 18, it will be assumed that N number of UEsare included in a group. For example, the group may correspond to agroup being related to groupcast SL communication. For example, theembodiment of FIG. 18 may be applied in accordance with the Option B.For example, the embodiment of FIG. 18 may be applied in accordance withthe Groupcast option 2.

Referring to FIG. 18, in step S1810, a transmitting UE may transmit aPSCCH and/or PSSCH to a plurality of receiving UEs. For example, thetransmitting UE may transmit SL information to the plurality ofreceiving UEs by using a PSCCH resource and/or a PSSCH resource. Forexample, the SL information may include at least one of SL controlinformation, SL data, SL packet, SL Transport Block (TB), SL messageand/or SL service.

In step S1820, the plurality of receiving UEs may determine an HARQfeedback resource. Additionally, for example, the transmitting UE maydetermine the HARQ feedback resource.

For example, in case the group is generated, an identifier (hereinafter,GUE_ID) being used within the group may be allocated per UE. In case thegroup is generated, a GUE_ID may be allocated per sub-group. Forexample, the GUE_ID may be generated by a specific UE and may then bedelivered to the UEs within the group. For example, the specific UE maybe a Group Owner (GO). For example, the GUE_ID may be configured by thenetwork or base station, or may be configured in advance (orpre-configured). For example, the GUE_ID may be differently allocatedfor each of the plurality of UEs within the group. For example, theGUE_ID may be differently allocated for each of the plurality ofsub-groups within the group.

For example, the plurality of receiving UEs may each determine an HARQfeedback resource based on its GUE_ID. For example, receiving UE 1 maydetermine the HARQ feedback resource by using the GUE_ID that isallocated to receiving UE 1, receiving UE 2 may determine the HARQfeedback resource by using the GUE_ID that is allocated to receiving UE2, and receiving UE N−1 may determine the HARQ feedback resource byusing the GUE_ID that is allocated to receiving UE N−1. Therefore, theHARQ feedback resource may be differently determined for each of theplurality of receiving UEs within the group.

For example, the remaining UEs (e.g., receiving UEs) excluding thetransmitting UE may sequentially use the plurality of HARQ feedbackresources (e.g., N−1 number of HARQ feedback resources) in accordancewith an increasing order of the GUE_ID. For example, the remaining UEs(e.g., receiving UEs) excluding the transmitting UE may sequentially usethe plurality of HARQ feedback resources (e.g., N−1 number of HARQfeedback resources) in accordance with a decreasing order of the GUE_ID.For example, the remaining UEs (e.g., receiving UEs) excluding thetransmitting UE may sequentially use the plurality of HARQ feedbackresources (e.g., N−1 number of HARQ feedback resources) in accordancewith an order of the GUE_ID that is derived based on a pre-configuredfunction/rule. For example, the plurality of HARQ feedback resources maybe configured in advance (or pre-configured). For example, thetransmitting UE may correspond to a UE that has transmitted the PSSCHand/or PSCCH to the plurality of receiving UEs.

For example, the remaining sub-groups excluding the transmitting UE maysequentially use the plurality of HARQ feedback resources in accordancewith an increasing order of the GUE_ID. For example, the remainingsub-groups excluding the transmitting UE may sequentially use theplurality of HARQ feedback resources in accordance with a decreasingorder of the GUE_ID. For example, the remaining sub-groups excluding thetransmitting UE may sequentially use the plurality of HARQ feedbackresources in accordance with an order of the GUE_ID that is derivedbased on a pre-configured function/rule. For example, the plurality ofHARQ feedback resources may be configured in advance (orpre-configured). For example, the transmitting UE may correspond to a UEthat has transmitted the PSSCH and/or PSCCH to the plurality ofreceiving UEs.

In step S1830, the plurality of receiving UEs may each transmit an HARQfeedback to the transmitting UE. For example, the plurality of receivingUEs may each transmit an HARQ feedback corresponding to the PSCCH and/orPSSCH to the transmitting UE. For example, the plurality of receivingUEs may each transmit the HARQ feedback to the transmitting UE by usingan HARQ feedback resource, which is determined based on the PSCCHresource and/or PSSCH resource.

For example, in case the receiving UE successfully receives the PSCCHand/or PSSCH, the HARQ feedback may be an HARQ ACK. For example, in casethe receiving UE fails to receive the PSCCH and/or PSSCH, the HARQfeedback may be at least one of an HARQ NACK and/or a discontinuousdetection (DTX).

According to an embodiment of the present disclosure, in order to reducean HARQ Round Trip Time (RTT), the HARQ feedback resource may become anFDM between UEs or sub-groups within the group. Herein, for example, inlight of a transmitting UE receiving an HARQ feedback from a receivingUE, in order to mitigate a Near-Far problem caused by in-band emission,power control associated with the HARQ feedback transmission may berequired. For example, in light of a PSSCH and/or PSCCH transmitting UEreceiving an HARQ feedback from a receiving UE, in order to mitigate aNear-Far problem caused by in-band emission, power control associatedwith the HARQ feedback transmission corresponding to the receiving UEmay be required.

According to an embodiment of the present disclosure, the UE maydetermine an HARQ feedback transmission power based on at least one ofan SL pathloss value derived/acquired based on a reference signal withinan SL channel, an SL RSRP value derived/acquired based on a referencesignal within an SL channel, a SL RSRQ value derived/acquired based on areference signal within an SL channel, an open-loop power controlparameter, and/or a closed-loop power control parameter. For example, incase the transmitting UE transmits a reference signal to the receivingUE via an SL channel, the receiving UE may determine an HARQ feedbacktransmission power based on at least one of an SL pathloss valuederived/acquired based on a reference signal within an SL channel, an SLRSRP value derived/acquired based on a reference signal within an SLchannel, a SL RSRQ value derived/acquired based on a reference signalwithin an SL channel, an open-loop power control parameter, and/or aclosed-loop power control parameter.

For example, a reference signal within the SL channel may be defined inadvance. For example, a reference signal within the SL channel may be aDMRS being transmitted within the PSSCH (i.e., PSSCH DMRS) or a DMRSbeing transmitted within the PSCCH (i.e., PSCCH DMRS). For example, areference signal within the SL channel may be a CSI-RS being transmittedwithin a PSSCH. For example, a reference signal within the SL channelmay be a reference signal being used for quality estimation (e.g., CQI,PMI, RI) of the SL channel. For example, a reference signal within theSL channel may be a reference signal being used for the measurement ofat least one of an SL pathloss value, an SL RSRP value, and/or an SLRSRQ value.

For example, the SL pathloss may be a pathloss corresponding to a linkbetween a transmitting UE and a receiving UE. For example, an open-looppower control parameter and/or a closed-loop power control parameter maybe configured in advance. For example, an open-loop power controlparameter may include a Po and/or alpha value.

For example, Po may be a power control parameter for averagelysatisfying a target error rate (e.g., Block Error Rate (BLER), FrameError Rate (FER)) related to packet/message transmission.Additionally/Alternatively, for example, Po may be a power controlparameter related to an average reception SINR between a transmitting UEand a receiving UE. For example, Po may be a power control parameterthat is specified to a UE, a resource pool, a service type, a servicepriority level, QoS requirements related to a service, a (frequency)resource size being used for SL transmission, an MCS value being usedfor SL transmission, a congestion level (e.g., CBR) related to theresource pool, and/or a cast type. For example, in case the HARQfeedback transmission power is calculated/derived based on an SL RSRPand/or SL RSRQ value/range, a different Po value/range may bemapped/configured per (pre-configured) SL RSRP and/or SL RSRQvalue/range.

For example, in case the HARQ feedback transmission power iscalculated/derived based on an SL pathloss, an alpha value may be aweighted value being applied to (measured) pathloss compensation.Additionally/Alternatively, for example, in case the HARQ feedbacktransmission power is calculated/derived based on an SL RSRP and/or SLRSRQ value/range, an alpha value may be a weighted value being appliedto a/an (measured) SL RSRP and/or SL RSRQ value/range.Additionally/Alternatively, for example, in case the HARQ feedbacktransmission power is calculated/derived based on an SL RSRP and/or SLRSRQ value/range, an alpha value may be a weighted value being appliedto an HARQ feedback transmission power being mapped/configured per(measured) SL RSRP and/or SL RSRQ value/range. Herein, for example, analpha value/range may be specifically configured for a UE, a resourcepool, a service type, a service priority level, QoS requirements relatedto a service, a (frequency) resource size being used for SLtransmission, an MCS value being used for SL transmission, a congestionlevel (e.g., CBR) related to the resource pool, and/or a cast type. Forexample, in case the HARQ feedback transmission power iscalculated/derived based on an SL RSRP and/or SL RSRQ value/range, adifferent alpha value/range may be mapped/configured per(pre-configured) SL RSRP and/or SL RSRQ value/range.

For example, in case the HARQ feedback transmission power iscalculated/derived based on an SL RSRP and/or SL RSRQ value/range, adifferent offset value/range may be mapped/configured per(pre-configured) SL RSRP and/or SL RSRQ value/range. A UE that hasmeasured the SL RSRP and/or SL RSRQ may apply the offset related to theSL RSRP value and/or SL RSRQ value to a (pre-configured normalized ornominal) (maximum) SL (HARQ feedback) transmission power, so as todetermine a final HARQ feedback transmission power. Herein, for example,the offset value/range may be specifically configured for a UE, aresource pool, a service type, a service priority level, QoSrequirements related to a service, a (frequency) resource size beingused for SL transmission, an MCS value being used for SL transmission, acongestion level (e.g., CBR) related to the resource pool, and/or a casttype.

For example, a different (normalized or nominal) (maximum) SL HARQfeedback transmission power may be mapped/configured per(pre-configured) SL RSRP and/or SL RSRQ value/range. For example, a(normalized or nominal) (maximum) SL HARQ feedback transmission powervalue/range may be specifically configured for a UE, a resource pool, aservice type, a service priority level, QoS requirements related to aservice, a (frequency) resource size being used for SL transmission, anMCS value being used for SL transmission, a congestion level (e.g., CBR)related to the resource pool, and/or a cast type.

For example, the reference signal and/or transmission power valuerelated to an SL channel including the reference signal may be signaledto a UE via a pre-defined channel. For example, the reference signaland/or transmission power value related to an SL channel including thereference signal may be transmitted to a receiving UE via a pre-definedchannel. For example, the pre-defined channel may correspond to a PSCCH.For example, the receiving UE may correspond to a UE measuring at leastone of an SL pathloss, an SL RSRP, and/or an SL RSRQ based on thereference signal.

For example, the open-loop power control parameter (and/or (maximum orminimum) HARQ feedback transmission power value being mapped/configuredper SL RSRP (and/or SL RSRQ) value/range) may be differently orindependently configured per service type, service priority level, SLcommunication type (e.g., unicast, groupcast, broadcast), (resource poolrelated) congestion level (e.g., Channel Busy Ratio (CBR)), sessionrelated to the service, PPPP related to the service, PPPR related to theservice, Block Error Rate (BLER) related to the service, target Signalto Interference plus Noise Ratio (SINR) related to the service, (minimumor maximum) target communication distance related to the service, and/orlatency budget related to the service.

Additionally/Alternatively, for example, a closed-loop transmissionpower control operation/parameter may be differently or independentlyconfigured per service type, service priority level, SL communicationtype (e.g., unicast, groupcast, broadcast), (resource pool related)congestion level (e.g., CBR), session related to the service, PPPPrelated to the service, PPPR related to the service, Block Error Rate(BLER) related to the service, target Signal to Interference plus NoiseRatio (SINR) related to the service, (minimum or maximum) targetcommunication distance related to the service, and/or latency budgetrelated to the service.

For example, an open-loop transmission power control parameter relatedto the HARQ feedback may be differently or independently configured fromthe open-loop transmission power control parameter related to the PSSCHand/or PSCCH. Additionally/Alternatively, for example, a closed-looptransmission power control operation/parameter related to the HARQfeedback may be differently or independently operated/configured fromthe closed-loop transmission power control operation/parameter relatedto the PSSCH and/or PSCCH.

According to an embodiment of the present disclosure, an FDM of an HARQresource may be authorized (or allowed) or configured only for receivingUEs having a distance from the transmitting UE, which receives the HARQfeedback, within a pre-determined threshold value.Additionally/Alternatively, for example, an FDM of an HARQ resource maybe authorized (or allowed) or configured only for receiving UEs havingan SL pathloss difference corresponding to a link between thetransmitting UE and the receiving UE within a predetermined thresholdvalue. Additionally/Alternatively, for example, an FDM of an HARQresource may be authorized (or allowed) or configured only for receivingUEs having an SL RSRP difference corresponding to a link between thetransmitting UE and the receiving UE within a predetermined thresholdvalue. Additionally/Alternatively, for example, an FDM of an HARQresource may be authorized (or allowed) or configured only for receivingUEs having an SL RSRQ difference corresponding to a link between thetransmitting UE and the receiving UE within a predetermined thresholdvalue.

For example, if a distance between each of the plurality of receivingUEs and the transmitting UE is within a pre-determined threshold value,the plurality of receiving UEs may transmit an HARQ feedback via aresource processed with FDM within the frequency axis.Additionally/Alternatively, for example, if a pathloss differencebetween each of the plurality of receiving UEs and the transmitting UEis within a pre-determined threshold value, the plurality of receivingUEs may transmit an HARQ feedback via a resource processed with FDMwithin the frequency axis. Additionally/Alternatively, for example, if a(measured) RSRP value difference between each of the plurality ofreceiving UEs and the transmitting UE is within a pre-determinedthreshold value, the plurality of receiving UEs may transmit an HARQfeedback via a resource processed with FDM within the frequency axis.Additionally/Alternatively, for example, if a (measured) RSRQ valuedifference between each of the plurality of receiving UEs and thetransmitting UE is within a pre-determined threshold value, theplurality of receiving UEs may transmit an HARQ feedback via a resourceprocessed with FDM within the frequency axis.

For example, it may not be preferable to process an HARQ feedbackresource with FDM among UEs or sub-groups within a group. For example,in case power control related to HARQ feedback transmission is notapplied, it may not be preferable to process an HARQ feedback resourcewith FDM among different UEs or different sub-groups within a group. Forexample, in case an HARQ feedback reception power difference amongdifferent UEs or different sub-groups within a group is greater than apre-determined threshold value, it may not be preferable to process anHARQ feedback resource with FDM among different UEs or differentsub-groups within the group. For example, in case an SL pathlossdifference among different UEs or different sub-groups within a group isgreater than a pre-determined threshold value, it may not be preferableto process an HARQ feedback resource with FDM among different UEs ordifferent sub-groups within the group. For example, in case an SL RSRPdifference among different UEs or different sub-groups within a group isgreater than a pre-determined threshold value, it may not be preferableto process an HARQ feedback resource with FDM among different UEs ordifferent sub-groups within the group. For example, in case an SL RSRQdifference among different UEs or different sub-groups within a group isgreater than a pre-determined threshold value, it may not be preferableto process an HARQ feedback resource with FDM among different UEs ordifferent sub-groups within the group.

For example, as mentioned in the above-described example, in case it isnot preferable to process the HARQ feedback resource with FDM, the HARQfeedback resource may be pseudo-randomly processed with FDM based on atleast one of a GUE_ID, an identifier related to a receiving UE, an SLHARQ process ID, and/or an identifier related to a transmitting UE. Forexample, the HARQ feedback resource may be pseudo-randomly determinedbased on at least one of a GUE_ID, an identifier related to a receivingUE, an SL HARQ process ID, and/or an identifier related to atransmitting UE. For example, the HARQ feedback resource may beprocessed with TDM or determined by a function having at least one of aGUE_ID, an identifier related to a receiving UE, an SL HARQ process ID,and/or an identifier related to a transmitting UE as an input parameter.For example, the HARQ feedback resource may be a HARQ feedback resourcefor each of a plurality of receiving UEs within the group. For example,the HARQ feedback resource may be a HARQ feedback resource for eachsub-group within the group. For example, the identifier related to thereceiving UE may correspond to a destination ID. For example, theidentifier related to the transmitting UE may be a source ID. Forexample, the function may be pre-defined in advance.

FIG. 19 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure. Theembodiment of FIG. 19 may be combined with other various embodiments.

Referring to FIG. 19, in step S1910, a transmitting UE may transmit aPSCCH and/or PSSCH to a receiving UE. For example, the transmitting UEmay transmit SL information to the receiving UE by using a PSCCHresource and/or a PSSCH resource. For example, the SL information mayinclude at least one of SL control information, SL data, SL packet, SLTransport Block (TB), SL message and/or SL service.

In step S1920, the receiving UE may determine an HARQ feedback resource.Additionally, for example, the transmitting UE may determine the HARQfeedback resource. For example, the receiving UE may be one of aplurality of receiving UEs performing groupcast communication within agroup.

For example, the HARQ feedback resource may be determined based on atleast one of the PSCCH resource, the PSSCH resource, and/or GUE_ID. Forexample, in case each of the plurality of receiving UEs within a groupfeeds-back an HARQ ACK or HARQ NACK to the transmitting UE by using adifferent PSFCH resource, the plurality of receiving UEs within thegroup may determine the HARQ feedback resource by using the GUE_ID. Forexample, the resource may include at least one of a time domainresource, a frequency domain resource, and/or a code domain resource.For example, the GUE_ID may correspond to information for identifying aUE within the group.

In step S1930, the receiving UE may transmit an HARQ feedback to thetransmitting UE. For example, the receiving UE may transmit an HARQfeedback corresponding to the PSCCH and/or PSSCH to the transmitting UE.For example, the receiving UE may transmit the HARQ feedback to thetransmitting UE by using an HARQ feedback resource, which is determinedbased on at least one of the PSCCH resource, the PSSCH resource, and/orthe GUE_ID.

For example, in case the receiving UE successfully receives the PSCCHand/or PSSCH, the HARQ feedback may be an HARQ ACK. For example, in casethe receiving UE fails to receive the PSCCH and/or PSSCH, the HARQfeedback may be at least one of an HARQ NACK and/or a discontinuousdetection (DTX).

According to the various embodiments of the present disclosure, in casea transmitting UE selects a PSSCH and/or PSCCH transmission resource byperforming a sensing operation, a problem of collision between HARQfeedback transmission related resources may not occur. For example, incase each of a plurality of transmitting UEs selects a different PSSCHand/or PSCCH transmission resource by performing a sensing operation,the HARQ feedback resource may be determined based on a PSSCH resourceand/or PSCCH resource. Therefore, among the UEs each having selected adifferent PSSCH and/or PSCCH transmission resource based on the sensingoperation, a collision between the HARQ feedback resources may beautomatically avoided.

According to the various embodiments of the present disclosure, in casethe transmitting UE transmits the same PSSCH and/or PSCCH to a pluralityof receiving UEs within the group, each of the plurality of receivingUEs may determine an HARQ feedback resource by using a different GUE_ID.Therefore, even though the plurality of receiving UEs within the grouphave received the same PSSCH and/or PSCCH, collision between the HARQfeedback resources may be prevented.

FIG. 20 shows a procedure for transmitting/receiving an HARQ feedback bya UE, in accordance with an embodiment of the present disclosure. Theembodiment of FIG. 20 may be combined with other various embodiments.

For example, an ID for identifying a UE within a group may be assigned(or allocated)/designated to each of the plurality of UEs within agroup. For example, the ID may be referred to as an inner ID. Forexample, the inner ID may be the same purpose or parameter as theGUE_ID. For example, for a specific groupcast traffic, an applicationlayer may deliver information on an inner ID of a UE and information ona number of UEs within a group to a V2X layer. For example, the UE maybe a UE transmitting the specific groupcast traffic. For example, for aspecific groupcast traffic, the application layer may not transmitinformation on an inner ID of a different UE within the group to the V2Xlayer. For example, the groupcast traffic may include at least one of agroupcast service, groupcast data, a groupcast packet, and/or agroupcast message.

For example, in an embodiment of FIG. 20, in case a transmitting UEintends to transmit a first traffic related to groupcast to a pluralityof receiving UEs within a group, an application layer of thetransmitting UE may deliver information on an inner ID (e.g., ID=2) ofthe transmitting UE and information on a number of UEs (e.g., 5) withinthe group to a V2X layer of the transmitting UE. For example, anapplication layer of receiving UE 1 may deliver information on an innerID (e.g., ID=0) of the receiving UE 1 and information on a number of UEs(e.g., 5) within the group to a V2X layer of the receiving UE 1. Forexample, an application layer of receiving UE 2 may deliver informationon an inner ID (e.g., ID=1) of the receiving UE 2 and information on anumber of UEs (e.g., 5) within the group to a V2X layer of the receivingUE 2. For example, an application layer of receiving UE 3 may deliverinformation on an inner ID (e.g., ID=3) of the receiving UE 3 andinformation on a number of UEs (e.g., 5) within the group to a V2X layerof the receiving UE 3. For example, an application layer of receiving UE4 may deliver information on an inner ID (e.g., ID=4) of the receivingUE 4 and information on a number of UEs (e.g., 5) within the group to aV2X layer of the receiving UE 4.

And, for example, a V2X layer of a UE may deliver information on aninner ID of the UE and information on a number of UEs within the groupto a V2X layer of the UE. Additionally, for example, a V2X layer of a UEmay collectively deliver L2 ID (e.g., source L2 ID, destination L2 ID)and/or QoS information, and so on, to an AS layer of the UE.

Referring to FIG. 20, in step S2010, a transmitting UE may transmit aspecific groupcast traffic to a plurality of receiving UEs. For example,the specific groupcast traffic may be transmitted via PSSCH and/orPSCCH.

In step S2020, the plurality of receiving UEs may determine an HARQfeedback resource. For example, each of the plurality of receiving UEs(e.g., an AS layer of each of the plurality of receiving UEs) maydetermine the HARQ feedback resource for a specific groupcast trafficbased on information on its inner ID and information on the number ofUEs within the group in accordance with a pre-defined rule.

For example, the transmitting UE may determine the HARQ feedbackresource (it is intended to receive). For example, the transmitting UEmay derive or determine HARQ feedback resources of the plurality ofreceiving UEs related to a specific groupcast traffic, based oninformation on the inner ID of each receiving UE and information on thenumber of UEs within the group.

For example, when an application layer provides information on inner IDsof UEs and information on a number of UEs within the group to a V2Xlayer of the UE, the UE may determine or view one of the Groupcastoption 1 or the Groupcast option 2 as a (selectable) HARQ feedbackoption for the specific groupcast traffic. For example, the V2X layer ofthe UE may determine or view one of the Groupcast option 1 or theGroupcast option 2 as a (selectable) HARQ feedback option for thespecific groupcast traffic. Additionally, depending upon whether or notpre-determined conditions are satisfied, the UE may finally determine orview one of the Groupcast option 1 and the Groupcast option 2 as an HARQfeedback option for the specific groupcast traffic. For example, in casethe HARQ feedback resources for each of a plurality of UEs participating(or being engaged) in the groupcast are all supported in the resourcepool, the UE may finally determine or view the Groupcast option 2 as theHARQ feedback option for the specific groupcast traffic. For example, incase the HARQ feedback resources for each of a plurality of UEsparticipating (or being engaged) in the groupcast are not all supportedin the resource pool, the UE may finally determine or view the Groupcastoption 1 as the HARQ feedback option for the specific groupcast traffic.For example, the determination (or decision) may be performed in the ASlayer of the UE.

For example, if an application layer does not provide the information onthe number of UEs within the group to a V2X layer of the UE, the UE maydetermine or view the Groupcast option 1 as the HARQ feedback option forthe specific groupcast traffic. For example, if an application layerdoes not provide the information on the inner IDs of the UEs and/orinformation on the number of UEs within the group to a V2X layer of theUE, the UE may determine or view the Groupcast option 1 as the HARQfeedback option for the specific groupcast traffic. For example, the V2Xlayer of the UE may determine or view the Groupcast option 1 as the HARQfeedback option for the specific groupcast traffic.

For example, if the application layer and/or the V2X layer provide(s)information on the inner IDs of the UEs and information on the number ofUEs within the group to an AS layer of the UE, the UE may determine orview one of the Groupcast option 1 and the Groupcast option 2 as a/an(selectable) HARQ feedback option for the specific groupcast traffic.For example, the AS layer of the UE may determine or view one of theGroupcast option 1 and the Groupcast option 2 as a/an (selectable) HARQfeedback option for the specific groupcast traffic. Additionally, forexample, depending upon whether or not pre-determined conditions aresatisfied, the UE may finally determine or view one of the Groupcastoption 1 and the Groupcast option 2 as an HARQ feedback option for thespecific groupcast traffic. For example, in case the HARQ feedbackresources for each of a plurality of UEs participating (or beingengaged) in the groupcast are all supported in the resource pool, the UEmay finally determine or view the Groupcast option 2 as the HARQfeedback option for the specific groupcast traffic. For example, in casethe HARQ feedback resources for each of a plurality of UEs participating(or being engaged) in the groupcast are not all supported in theresource pool, the UE may finally determine or view the Groupcast option1 as the HARQ feedback option for the specific groupcast traffic. Forexample, the determination (or decision) may be performed in the ASlayer of the UE.

For example, if an application layer and/or V2X layer do/does notprovide the information on the number of UEs within the group to an ASlayer of the UE, the UE may determine or view the Groupcast option 1 asthe HARQ feedback option for the specific groupcast traffic. Forexample, if an application layer and/or V2X layer do/does not providethe information on the inner IDs of the UEs and/or information on thenumber of UEs within the group to an AS layer of the UE, the UE maydetermine or view the Groupcast option 1 as the HARQ feedback option forthe specific groupcast traffic. For example, the AS layer of the UE maydetermine or view the Groupcast option 1 as the HARQ feedback option forthe specific groupcast traffic.

For example, whether or not at least one of the Groupcast option 1 andthe Groupcast option 2 is supported may be, resource pool-specifically,signaled for a UE. For example, whether or not at least one of theGroupcast option 1 and the Groupcast option 2 is supported may be,resource pool-specifically, signaled for a UE per service type, casttype, or QoS requirement. For example, whether or not a PSFCH resourcerelated to the Groupcast option 1 is configured may be, resourcepool-specifically, signaled for a UE per service type, cast type, or QoSrequirement. For example, whether or not a PSFCH resource related to theGroupcast option 2 is configured may be, resource pool-specifically,signaled for a UE per service type, cast type, or QoS requirement.

In step S2030, the transmitting UE may receive an HARQ feedback from theplurality of receiving UEs. For example, the transmitting UE may receivea Groupcast option 1 based HARQ feedback from the plurality of receivingUEs. For example, the transmitting UE may receive a Groupcast option 2based HARQ feedback from the plurality of receiving UEs.

For example, a specific groupcast option based HARQ feedback operationmay be required for a specific groupcast traffic. For example, in casethe reliability requirement related to the service is high, if thetransmitting UE transmits the corresponding service to the receiving UE,the receiving UE is required to perform a Groupcast option 2 based HARQfeedback operation. If the receiving UE performs a Groupcast option 1based HARQ feedback operation for the service, a DTX problem may occur.Therefore, the receiving UE is required to perform a Groupcast option 2based HARQ feedback operation for a service having a high reliabilityrequirement. For example, the DTX problem may be a problem where thetransmitting UE misinterprets that the receiving UE has successfullyreceived the PSCCH and PSSCH, while the receiving UE has actually failedto receive the PSCCH and does not transmit a NACK to the transmittingUE. For example, due to the DTX problem, it may be difficult to satisfythe reliability requirement of the service. Therefore, in case aspecific groupcast option is not supported in the resource pool, forexample, in case a specific groupcast option is not supported for thecorresponding traffic and/or service, the transmitting UE may perform ablind re-transmission operation. For example, if a PSFCH resourcerelated to a specific groupcast option is not configured, thetransmitting UE may perform a blind re-transmission operation. Forexample, the transmitting UE may perform re-transmission withoutreceiving the HARQ feedback from the receiving UE.

According to the various embodiments of the present disclosure,reliability in the SL HARQ feedback transmission may be enhanced,latency in the SL service may be reduced, and/or reliability in the SLservice may be enhanced.

FIG. 21 shows a method for transmitting an SL HARQ feedback by a firstdevice 100, in accordance with an embodiment of the present disclosure.The embodiment of FIG. 21 may be combined with other variousembodiments.

Referring to FIG. 21, in step S2110, a first device 100 may receive aPhysical Sidelink Shared Channel (PSSCH) from a second device 200.

In step S2120, the first device 100 may transmit an SL HARQ feedbackrelated to the PSSCH to the second device 200. For example, a resourcein which the SL HARQ feedback is transmitted may be determined based onan identifier (ID) of the first device 100. For example, the ID of thefirst device 100 may be an ID for identifying the first device 100 amongthe plurality of UEs performing groupcast communication within thegroup. For example, the IDs of the plurality of UEs may be differentwithin the group.

For example, the resource in which the SL HARQ feedback is transmittedmay be determined based on the information related to the PSSCH. Forexample, the information on the resource related to the PSSCH mayinclude at least one of information on a time related to the PSSCH andinformation on a frequency related to the PSSCH.

Additionally, the first device 100 may receive a Physical SidelinkControl Channel (PSCCH) from the second device 200. For example, aresource in which the SL HARQ feedback is being transmitted may bedetermined based on information on a resource related to the PSCCH. Forexample, the information on the resource related to the PSCCH mayinclude at least one of information on a time related to the PSCCH andinformation on a frequency related to the PSCCH.

For example, a time gap between a resource related to the PSSCH and aresource in which the SL HARQ feedback is transmitted may be configuredfor the first device 100 and the second device 200.

For example, the resource in which the SL HARQ feedback is transmittedmay be included in a frequency domain related to the PSSCH.

Additionally, the first device 100 may measure a channel status betweenthe first device 100 and the second device 200 based on a DMRS includedin the PSSCH, and the first device 100 may determine a transmissionpower of the SL HARQ feedback based on the channel status. For example,the transmission power of the SL HARQ feedback may be determined basedon at least one of a service type, a service priority level, an SLcommunication type, a session related to the service, ProSe Per PacketPriority (PPPP) related to the service, ProSe Per Packet Reliability(PPPR) related to the service, Block Error Rate (BLER) related to theservice, Signal to Interference plus Noise Ratio (SINR) related to theservice, or a latency budget related to the service.

The proposed method may be performed by a device according to thevarious embodiments of the present disclosure. Firstly, a processor 102of the first device 100 may control a transceiver 106 so that the firstdevice 100 can receive the Physical Sidelink Shared Channel (PSSCH) fromthe second device 200. Thereafter, the processor 102 of the first device100 may control the transceiver 106 so that the first device 100 cantransmit an SL HARQ feedback related to the PSSCH to the second device200.

FIG. 22 shows a method for receiving an SL HARQ feedback by a seconddevice 200, in accordance with an embodiment of the present disclosure.The embodiment of FIG. 22 may be combined with other variousembodiments.

Referring to FIG. 22, in step S2210, the second device 200 may transmita Physical Sidelink Shared Channel (PSSCH) to a plurality of UEs withinthe group.

In step S2220, the second device 200 may receive an SL HARQ feedbackrelated to the PSSCH from the plurality of UEs. For example, theresource in which the SL HARQ feedback is received may be determinedbased on identifiers (IDs) of the plurality of UEs. For example, the IDsof the plurality of UEs may be different within the group. For example,the SL HARQ feedback may be received from the plurality of UEs withinthe group on different resources.

The proposed method may be performed by a device according to thevarious embodiments of the present disclosure. Firstly, a processor 202of the second device 200 may control a transceiver 206 so that thesecond device 200 can transmit the Physical Sidelink Shared Channel(PSSCH) to a plurality of UEs within the group. Thereafter, theprocessor 202 of the second device 200 may control the transceiver 206so that the second device 200 can receive SL HARQ feedback related tothe PSSCH from the plurality of UEs.

Various embodiments of the present disclosure may be independentlyimplemented. Alternatively, various embodiments of the presentdisclosure may be implemented as a combination or integration of two ormore of the embodiments. For example, although the various embodimentsof the present disclosure are described based on a 3GPP system forsimplicity, the various embodiments of the present disclosure may alsobe extendedly applied to other systems apart from the 3GPP system.

Hereinafter, an apparatus to which various embodiments of the presentdisclosure can be applied will be described.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the present disclosure described inthis document may be applied to, without being limited to, variousfields requiring wireless communication/connection (e.g., 5G) betweendevices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 23 shows a communication system 1, in accordance with an embodimentof the present disclosure.

Referring to FIG. 23, a communication system 1 to which variousembodiments of the present disclosure are applied includes wirelessdevices, Base Stations (BSs), and a network. Herein, the wirelessdevices represent devices performing communication using Radio AccessTechnology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE))and may be referred to as communication/radio/5G devices. The wirelessdevices may include, without being limited to, a robot 100 a, vehicles100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-helddevice 100 d, a home appliance 100 e, an Internet of Things (IoT) device100 f, and an Artificial Intelligence (AI) device/server 400. Forexample, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous vehicle, and a vehicle capable ofperforming communication between vehicles. Herein, the vehicles mayinclude an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR devicemay include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality(MR) device and may be implemented in the form of a Head-Mounted Device(HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, asmartphone, a computer, a wearable device, a home appliance device, adigital signage, a vehicle, a robot, etc. The hand-held device mayinclude a smartphone, a smartpad, a wearable device (e.g., a smartwatchor a smartglasses), and a computer (e.g., a notebook). The homeappliance may include a TV, a refrigerator, and a washing machine. TheIoT device may include a sensor and a smartmeter. For example, the BSsand the network may be implemented as wireless devices and a specificwireless device 200 a may operate as a BS/network node with respect toother wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 24 shows wireless devices, in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 24, a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through various RATs (e.g., LTEand NR). Herein, {the first wireless device 100 and the second wirelessdevice 200} may correspond to {the wireless device 100 x and the BS 200}and/or {the wireless device 100 x and the wireless device 100 x} of FIG.23.

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store various informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store various informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels, etc., from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc., using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels,etc., processed using the one or more processors 102 and 202 from thebase band signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

FIG. 25 shows a signal process circuit for a transmission signal, inaccordance with an embodiment of the present disclosure.

Referring to FIG. 25, a signal processing circuit 1000 may includescramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040,resource mappers 1050, and signal generators 1060. An operation/functionof FIG. 25 may be performed, without being limited to, the processors102 and 202 and/or the transceivers 106 and 206 of FIG. 24. Hardwareelements of FIG. 25 may be implemented by the processors 102 and 202and/or the transceivers 106 and 206 of FIG. 24. For example, blocks 1010to 1060 may be implemented by the processors 102 and 202 of FIG. 24.Alternatively, the blocks 1010 to 1050 may be implemented by theprocessors 102 and 202 of FIG. 24 and the block 1060 may be implementedby the transceivers 106 and 206 of FIG. 24.

Codewords may be converted into radio signals via the signal processingcircuit 1000 of FIG. 25. Herein, the codewords are encoded bit sequencesof information blocks. The information blocks may include transportblocks (e.g., a UL-SCH transport block, a DL-SCH transport block). Theradio signals may be transmitted through various physical channels(e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bitsequences by the scramblers 1010. Scramble sequences used for scramblingmay be generated based on an initialization value, and theinitialization value may include ID information of a wireless device.The scrambled bit sequences may be modulated to modulation symbolsequences by the modulators 1020. A modulation scheme may includepi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying(m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complexmodulation symbol sequences may be mapped to one or more transportlayers by the layer mapper 1030. Modulation symbols of each transportlayer may be mapped (precoded) to corresponding antenna port(s) by theprecoder 1040. Outputs z of the precoder 1040 may be obtained bymultiplying outputs y of the layer mapper 1030 by an N*M precodingmatrix W. Herein, N is the number of antenna ports and M is the numberof transport layers. The precoder 1040 may perform precoding afterperforming transform precoding (e.g., DFT) for complex modulationsymbols. Alternatively, the precoder 1040 may perform precoding withoutperforming transform precoding.

The resource mappers 1050 may map modulation symbols of each antennaport to time-frequency resources. The time-frequency resources mayinclude a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMAsymbols) in the time domain and a plurality of subcarriers in thefrequency domain. The signal generators 1060 may generate radio signalsfrom the mapped modulation symbols and the generated radio signals maybe transmitted to other devices through each antenna. For this purpose,the signal generators 1060 may include Inverse Fast Fourier Transform(IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-AnalogConverters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wirelessdevice may be configured in a reverse manner of the signal processingprocedures 1010 to 1060 of FIG. 25. For example, the wireless devices(e.g., 100 and 200 of FIG. 24) may receive radio signals from theexterior through the antenna ports/transceivers. The received radiosignals may be converted into baseband signals through signal restorers.To this end, the signal restorers may include frequency downlinkconverters, Analog-to-Digital Converters (ADCs), CP remover, and FastFourier Transform (FFT) modules. Next, the baseband signals may berestored to codewords through a resource demapping procedure, apostcoding procedure, a demodulation processor, and a descramblingprocedure. The codewords may be restored to original information blocksthrough decoding. Therefore, a signal processing circuit (notillustrated) for a reception signal may include signal restorers,resource demappers, a postcoder, demodulators, descramblers, anddecoders.

FIG. 26 shows another example of a wireless device, in accordance withan embodiment of the present disclosure. The wireless device may beimplemented in various forms according to a use-case/service (refer toFIG. 23).

Referring to FIG. 26, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 24 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 and/or the one or morememories 104 and 204 of FIG. 24. For example, the transceiver(s) 114 mayinclude the one or more transceivers 106 and 206 and/or the one or moreantennas 108 and 208 of FIG. 24. The control unit 120 is electricallyconnected to the communication unit 110, the memory 130, and theadditional components 140 and controls overall operation of the wirelessdevices. For example, the control unit 120 may control anelectric/mechanical operation of the wireless device based onprograms/code/commands/information stored in the memory unit 130. Thecontrol unit 120 may transmit the information stored in the memory unit130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 23), the vehicles (100 b-1 and 100 b-2 of FIG. 23), the XRdevice (100 c of FIG. 23), the hand-held device (100 d of FIG. 23), thehome appliance (100 e of FIG. 23), the IoT device (100 f of FIG. 23), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 23), the BSs (200 of FIG. 23), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 26, the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 26 will be described indetail with reference to the drawings.

FIG. 27 shows a hand-held device, in accordance with an embodiment ofthe present disclosure. The hand-held device may include a smartphone, asmartpad, a wearable device (e.g., a smartwatch or a smartglasses), or aportable computer (e.g., a notebook). The hand-held device may bereferred to as a mobile station (MS), a user terminal (UT), a MobileSubscriber Station (MSS), a Subscriber Station (SS), an Advanced MobileStation (AMS), or a Wireless Terminal (WT).

Referring to FIG. 27, a hand-held device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an I/O unit 140 c.The antenna unit 108 may be configured as a part of the communicationunit 110. Blocks 110 to 130/140 a to 140 c correspond to the blocks 110to 130/140 of FIG. 26, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an Application Processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. The memory unit 130 may store input/output data/information.The power supply unit 140 a may supply power to the hand-held device 100and include a wired/wireless charging circuit, a battery, etc. Theinterface unit 140 b may support connection of the hand-held device 100to other external devices. The interface unit 140 b may include variousports (e.g., an audio I/O port and a video I/O port) for connection withexternal devices. The I/O unit 140 c may input or output videoinformation/signals, audio information/signals, data, and/or informationinput by a user. The I/O unit 140 c may include a camera, a microphone,a user input unit, a display unit 140 d, a speaker, and/or a hapticmodule. As an example, in the case of data communication, the I/O unit140 c may acquire information/signals (e.g., touch, text, voice, images,or video) input by a user and the acquired information/signals may bestored in the memory unit 130. The communication unit 110 may convertthe information/signals stored in the memory into radio signals andtransmit the converted radio signals to other wireless devices directlyor to a BS. The communication unit 110 may receive radio signals fromother wireless devices or the BS and then restore the received radiosignals into original information/signals. The restoredinformation/signals may be stored in the memory unit 130 and may beoutput as various types (e.g., text, voice, images, video, or haptic)through the I/O unit 140 c.

FIG. 28 shows a vehicle or an autonomous vehicle, in accordance with anembodiment of the present disclosure. The vehicle or autonomous vehiclemay be implemented by a mobile robot, a car, a train, a manned/unmannedAerial Vehicle (AV), a ship, etc.

Referring to FIG. 28, a vehicle or autonomous vehicle 100 may include anantenna unit 108, a communication unit 110, a control unit 120, adriving unit 140 a, a power supply unit 140 b, a sensor unit 140 c, andan autonomous driving unit 140 d. The antenna unit 108 may be configuredas a part of the communication unit 110. The blocks 110/130/140 a to 140d correspond to the blocks 110/130/140 of FIG. 26, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous vehicle 100. The control unit 120 may includean Electronic Control Unit (ECU). The driving unit 140 a may cause thevehicle or the autonomous vehicle 100 to drive on a road. The drivingunit 140 a may include an engine, a motor, a powertrain, a wheel, abrake, a steering device, etc. The power supply unit 140 b may supplypower to the vehicle or the autonomous vehicle 100 and include awired/wireless charging circuit, a battery, etc. The sensor unit 140 cmay acquire a vehicle state, ambient environment information, userinformation, etc. The sensor unit 140 c may include an InertialMeasurement Unit (IMU) sensor, a collision sensor, a wheel sensor, aspeed sensor, a slope sensor, a weight sensor, a heading sensor, aposition module, a vehicle forward/backward sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illumination sensor, a pedalposition sensor, etc. The autonomous driving unit 140 d may implementtechnology for maintaining a lane on which a vehicle is driving,technology for automatically adjusting speed, such as adaptive cruisecontrol, technology for autonomously driving along a determined path,technology for driving by automatically setting a path if a destinationis set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc., from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous vehicle 100 may movealong the autonomous driving path according to the driving plan (e.g.,speed/direction control). In the middle of autonomous driving, thecommunication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous vehicles and provide the predicted traffic information datato the vehicles or the autonomous vehicles.

FIG. 29 shows a vehicle, in accordance with an embodiment of the presentdisclosure. The vehicle may be implemented as a transport means, anaerial vehicle, a ship, etc.

Referring to FIG. 29, a vehicle 100 may include a communication unit110, a control unit 120, a memory unit 130, an I/O unit 140 a, and apositioning unit 140 b. Herein, the blocks 110 to 130/140 a and 140 bcorrespond to blocks 110 to 130/140 of FIG. 26.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as other vehiclesor BSs. The control unit 120 may perform various operations bycontrolling constituent elements of the vehicle 100. The memory unit 130may store data/parameters/programs/code/commands for supporting variousfunctions of the vehicle 100. The I/O unit 140 a may output an AR/VRobject based on information within the memory unit 130. The I/O unit 140a may include an HUD. The positioning unit 140 b may acquire informationabout the position of the vehicle 100. The position information mayinclude information about an absolute position of the vehicle 100,information about the position of the vehicle 100 within a travelinglane, acceleration information, and information about the position ofthe vehicle 100 from a neighboring vehicle. The positioning unit 140 bmay include a GPS and various sensors.

As an example, the communication unit 110 of the vehicle 100 may receivemap information and traffic information from an external server andstore the received information in the memory unit 130. The positioningunit 140 b may obtain the vehicle position information through the GPSand various sensors and store the obtained information in the memoryunit 130. The control unit 120 may generate a virtual object based onthe map information, traffic information, and vehicle positioninformation and the I/O unit 140 a may display the generated virtualobject in a window in the vehicle 1410 and 1420. The control unit 120may determine whether the vehicle 100 normally drives within a travelinglane, based on the vehicle position information. If the vehicle 100abnormally exits from the traveling lane, the control unit 120 maydisplay a warning on the window in the vehicle through the I/O unit 140a. In addition, the control unit 120 may broadcast a warning messageregarding driving abnormity to neighboring vehicles through thecommunication unit 110. According to situation, the control unit 120 maytransmit the vehicle position information and the information aboutdriving/vehicle abnormality to related organizations.

FIG. 30 shows an XR device, in accordance with an embodiment of thepresent disclosure. The XR device may be implemented by an HMD, an HUDmounted in a vehicle, a television, a smartphone, a computer, a wearabledevice, a home appliance, a digital signage, a vehicle, a robot, etc.

Referring to FIG. 30, an XR device 100 a may include a communicationunit 110, a control unit 120, a memory unit 130, an I/O unit 140 a, asensor unit 140 b, and a power supply unit 140 c. Herein, the blocks 110to 130/140 a to 140 c correspond to the blocks 110 to 130/140 of FIG.26, respectively.

The communication unit 110 may transmit and receive signals (e.g., mediadata and control signals) to and from external devices such as otherwireless devices, hand-held devices, or media servers. The media datamay include video, images, and sound. The control unit 120 may performvarious operations by controlling constituent elements of the XR device100 a. For example, the control unit 120 may be configured to controland/or perform procedures such as video/image acquisition, (video/image)encoding, and metadata generation and processing. The memory unit 130may store data/parameters/programs/code/commands needed to drive the XRdevice 100 a/generate XR object. The I/O unit 140 a may obtain controlinformation and data from the exterior and output the generated XRobject. The I/O unit 140 a may include a camera, a microphone, a userinput unit, a display unit, a speaker, and/or a haptic module. Thesensor unit 140 b may obtain an XR device state, surrounding environmentinformation, user information, etc. The sensor unit 140 b may include aproximity sensor, an illumination sensor, an acceleration sensor, amagnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IRsensor, a fingerprint recognition sensor, an ultrasonic sensor, a lightsensor, a microphone and/or a radar. The power supply unit 140 c maysupply power to the XR device 100 a and include a wired/wirelesscharging circuit, a battery, etc.

For example, the memory unit 130 of the XR device 100 a may includeinformation (e.g., data) needed to generate the XR object (e.g., anAR/VR/MR object). The I/O unit 140 a may receive a command formanipulating the XR device 100 a from a user and the control unit 120may drive the XR device 100 a according to a driving command of a user.For example, when a user desires to watch a film or news through the XRdevice 100 a, the control unit 120 transmits content request informationto another device (e.g., a hand-held device 100 b) or a media serverthrough the communication unit 130. The communication unit 130 maydownload/stream content such as films or news from another device (e.g.,the hand-held device 100 b) or the media server to the memory unit 130.The control unit 120 may control and/or perform procedures such asvideo/image acquisition, (video/image) encoding, and metadatageneration/processing with respect to the content and generate/outputthe XR object based on information about a surrounding space or a realobject obtained through the I/O unit 140 a/sensor unit 140 b.

The XR device 100 a may be wirelessly connected to the hand-held device100 b through the communication unit 110 and the operation of the XRdevice 100 a may be controlled by the hand-held device 100 b. Forexample, the hand-held device 100 b may operate as a controller of theXR device 100 a. To this end, the XR device 100 a may obtain informationabout a 3D position of the hand-held device 100 b and generate andoutput an XR object corresponding to the hand-held device 100 b.

FIG. 31 shows a robot, in accordance with an embodiment of the presentdisclosure. The robot may be categorized into an industrial robot, amedical robot, a household robot, a military robot, etc., according to aused purpose or field.

Referring to FIG. 31, a robot 100 may include a communication unit 110,a control unit 120, a memory unit 130, an I/O unit 140 a, a sensor unit140 b, and a driving unit 140 c. Herein, the blocks 110 to 130/140 a to140 c correspond to the blocks 110 to 130/140 of FIG. 26, respectively.

The communication unit 110 may transmit and receive signals (e.g.,driving information and control signals) to and from external devicessuch as other wireless devices, other robots, or control servers. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the robot 100. The memory unit 130 may storedata/parameters/programs/code/commands for supporting various functionsof the robot 100. The I/O unit 140 a may obtain information from theexterior of the robot 100 and output information to the exterior of therobot 100. The I/O unit 140 a may include a camera, a microphone, a userinput unit, a display unit, a speaker, and/or a haptic module. Thesensor unit 140 b may obtain internal information of the robot 100,surrounding environment information, user information, etc. The sensorunit 140 b may include a proximity sensor, an illumination sensor, anacceleration sensor, a magnetic sensor, a gyro sensor, an inertialsensor, an IR sensor, a fingerprint recognition sensor, an ultrasonicsensor, a light sensor, a microphone, a radar, etc. The driving unit 140c may perform various physical operations such as movement of robotjoints. In addition, the driving unit 140 c may cause the robot 100 totravel on the road or to fly. The driving unit 140 c may include anactuator, a motor, a wheel, a brake, a propeller, etc.

FIG. 32 shows an AI device, in accordance with an embodiment of thepresent disclosure. The AI device may be implemented by a fixed deviceor a mobile device, such as a TV, a projector, a smartphone, a PC, anotebook, a digital broadcast terminal, a tablet PC, a wearable device,a Set Top Box (STB), a radio, a washing machine, a refrigerator, adigital signage, a robot, a vehicle, etc.

Referring to FIG. 32, an AI device 100 may include a communication unit110, a control unit 120, a memory unit 130, an I/O unit 140 a/140 b, alearning processor unit 140 c, and a sensor unit 140 d. The blocks 110to 130/140 a to 140 d correspond to blocks 110 to 130/140 of FIG. 26,respectively.

The communication unit 110 may transmit and receive wired/radio signals(e.g., sensor information, user input, learning models, or controlsignals) to and from external devices such as other AI devices (e.g.,100 x, 200, or 400 of FIG. 23) or an AI server (e.g., 400 of FIG. 23)using wired/wireless communication technology. To this end, thecommunication unit 110 may transmit information within the memory unit130 to an external device and transmit a signal received from theexternal device to the memory unit 130.

The control unit 120 may determine at least one feasible operation ofthe AI device 100, based on information which is determined or generatedusing a data analysis algorithm or a machine learning algorithm. Thecontrol unit 120 may perform an operation determined by controllingconstituent elements of the AI device 100. For example, the control unit120 may request, search, receive, or use data of the learning processorunit 140 c or the memory unit 130 and control the constituent elementsof the AI device 100 to perform a predicted operation or an operationdetermined to be preferred among at least one feasible operation. Thecontrol unit 120 may collect history information including the operationcontents of the AI device 100 and operation feedback by a user and storethe collected information in the memory unit 130 or the learningprocessor unit 140 c or transmit the collected information to anexternal device such as an AI server (400 of FIG. 23). The collectedhistory information may be used to update a learning model.

The memory unit 130 may store data for supporting various functions ofthe AI device 100. For example, the memory unit 130 may store dataobtained from the input unit 140 a, data obtained from the communicationunit 110, output data of the learning processor unit 140 c, and dataobtained from the sensor unit 140. The memory unit 130 may store controlinformation and/or software code needed to operate/drive the controlunit 120.

The input unit 140 a may acquire various types of data from the exteriorof the AI device 100. For example, the input unit 140 a may acquirelearning data for model learning, and input data to which the learningmodel is to be applied. The input unit 140 a may include a camera, amicrophone, and/or a user input unit. The output unit 140 b may generateoutput related to a visual, auditory, or tactile sense. The output unit140 b may include a display unit, a speaker, and/or a haptic module. Thesensing unit 140 may obtain at least one of internal information of theAI device 100, surrounding environment information of the AI device 100,and user information, using various sensors. The sensor unit 140 mayinclude a proximity sensor, an illumination sensor, an accelerationsensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGBsensor, an IR sensor, a fingerprint recognition sensor, an ultrasonicsensor, a light sensor, a microphone, and/or a radar.

The learning processor unit 140 c may learn a model consisting ofartificial neural networks, using learning data. The learning processorunit 140 c may perform AI processing together with the learningprocessor unit of the AI server (400 of FIG. 23). The learning processorunit 140 c may process information received from an external devicethrough the communication unit 110 and/or information stored in thememory unit 130. In addition, an output value of the learning processorunit 140 c may be transmitted to the external device through thecommunication unit 110 and may be stored in the memory unit 130.

Claims in the present description can be combined in various ways. Forinstance, technical features in method claims of the present descriptioncan be combined to be implemented or performed in an apparatus, andtechnical features in apparatus claims can be combined to be implementedor performed in a method. Further, technical features in method claim(s)and apparatus claim(s) can be combined to be implemented or performed inan apparatus. Further, technical features in method claim(s) andapparatus claim(s) can be combined to be implemented or performed in amethod.

1. A method of transmitting a Sidelink Hybrid Automatic Repeat Request(SL HARQ) feedback by a first device, comprising: receiving a PhysicalSidelink Shared Channel (PSSCH) from a second device; and transmitting aSL HARQ feedback related to the PSSCH to the second device, wherein aresource in which the SL HARQ feedback is transmitted is determinedbased on an identifier (ID) of the first device and an ID of the seconddevice, and wherein the ID of the first device is an ID for identifyingthe first device among a plurality of user equipments (UEs) performinggroupcast communication within a group.
 2. The method of claim 1,wherein the group is a group to which the first device 10 and the seconddevice belong.
 3. The method of claim 1, wherein IDs of the plurality ofUEs are different within the group.
 4. The method of claim 1, wherein aresource in which the SL HARQ feedback is transmitted is determinedbased on information on a resource related to the PSSCH.
 5. The methodof claim 4, wherein the information on a resource related to the PSSCHincludes at least one of (i) information on a time related to the PSSCHor (ii) information on a frequency related to the PSSCH.
 6. The methodof claim 1, further comprising: receiving a Physical Sidelink ControlChannel (PSCCH) from the second device, wherein a resource in which theSL HARQ feedback is transmitted is determined based on information on aresource related to the PSCCH.
 7. The method of claim 6, wherein theinformation on the resource related to the PSCCH includes at least oneof ci) information on a time related to the PSCCH or (ii) information ona frequency related to the PSCCH.
 8. The method of claim 1, wherein atime gap between a resource related to the PSSCH and a resource in whichthe SL HARQ feedback is transmitted is configured for the first deviceand the second device.
 9. The method of claim 1, wherein the resource inwhich the SL HARQ feedback is transmitted is included in a frequencydomain related to the PSSCH.
 10. The method of claim 1, furthercomprising: measuring a channel status between the first device and thesecond device based on a DMRS included in the PSSCH; and determining atransmission power of the SL HARQ feedback based on the channel status.11. The method of claim 10, wherein a transmission power of the SL HARQfeedback is determined based on at least one of a service type, aservice priority level, an SL communication type, a session related tothe service, a ProSe Per Packet Priority (PPPP) related to the service,a ProSe Per Packet Reliability (PPPR) related to the service, a targetBlock Error Rate (BLER) related to the service, a target Signal toInterference plus Noise Ratio (SINR) related to the service, ora latencybudget related to the service.
 12. A method for receiving a SidelinkHybrid Automatic Repeat Request (SL HARQ) feedback by a second device,the method comprising: transmitting a Physical Sidelink Shared Channel(PSSCH) to a plurality of user equipments (UEs) within a group; andreceiving an SL HARQ feedback related to the PSSCH from the plurality ofUEs, wherein a resource in which the SL HARQ feedback is received isdetermined based on identifiers (IDs) of the plurality of UEs, andwherein the IDs of the plurality of UEs are IDs for identifying each ofthe plurality of UEs among the plurality of UEs performing groupcastcommunication within a group.
 13. The method of claim 12, wherein theIDs of the plurality of UEs are different within the group.
 14. Themethod of claim 12, wherein the SL HARQ feedback is received from theplurality of UEs within the group on different resources.
 15. A firstdevice configured to transmit a Sidelink Hybrid Automatic Repeat RequestSL HARQ) feedback, the first device comprising: one or moretransceivers; one or more processors; and one or more computer memoriesoperably connectable to the one or more processors and storinginformation that, when executed by the one or more processors, performoperations comprising: receiving, through the transceiver, a PhysicalSidelink Shared Channel (PSSCH) from a second device, and transmitting,through the transceiver, a SL HARQ feedback related to the PSSCH to thesecond device, wherein a resource in which the SL HARQ feedback istransmitted is determined based on an identifier (ID) of the firstdevice and an ID of the second device, and wherein the ID of the firstdevice is an ID for identifying the first device among a plurality ofuser equipments (UEs) performing groupcast communication within a group.16. The method of claim 8, wherein the time gap is configured for thefirst device and the second device in a resource pool.
 17. The method ofclaim 8, wherein the time gap is configured for the first device and thesecond device per a resource pool.
 18. The method of claim 8, whereinthe time gap configured for the first device in a resource pool and thetime gap configured for the second device in the resource pool is same.